INDIABIX-Part 1-ELEX-MCQs.pdf

March 17, 2019 | Author: Jade Mark Ramos | Category: Diode, P–N Junction, Bipolar Junction Transistor, Semiconductors, Transistor

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INDIABIX ELECTRONICS

SEMICONDUCTORS 1. A silicon diode measures a low value of resistance with the meter leads in both positions. The trouble, if any, is A. the diode is open. B. the diode is shorted to ground. C. the diode is internally shorted. D. the diode is working correctly. 2. Single-element semiconductors are characterized by atoms with ____ valence electrons. A. 3 B. 4 C. 5 D. 2 3. Under normal conditions a diode conducts current when it is A. reverse-biased. B. forward-biased. C. avalanched. D. saturated. 4. A diode conducts when it is forwardbiased, and the anode is connected to the ________ through a limiting resistor. A. positive supply B. negative supply C. cathode D. anode 5. As the forward current through a silicon diode increases, the internal resistance A. increases. B. decreases. C. remains the same. 6. The movement of free electrons in a conductor is called A. voltage. B. current. C. recombination. D. equilibrium. 7. For a forward-biased diode, the barrier potential ________ as temperature increases. A. decreases B. remains constant C. increases 8. The wide end arrow on a schematic indicates the ________ of a diode. A. ground B. direction of electron flow C. cathode D. anode

9. An n-type semiconductor material A. is intrinsic. B. has trivalent impurity atoms added. C. has pentavalent impurity atoms added. D. requires no doping. 10. For a forward-biased diode, as temperature is ________, the forward current ________ for a given value of forward voltage. A. decreased, increases B. increased, increases C. increased, decreases D. decreased, decreases 11. Which statement best describes an insulator? A. A material with many free electrons. B. A material doped to have some free electrons. C. A material with few free electrons. D. No description fits. 12. Effectively, how many valence electrons are there in each atom within a silicon crystal? A. 2 B. 4 C. 8 D. 16 13. The boundary between p-type material and n-type material is called A. a diode. B. a reverse-biased diode. C. a pn junction. D. a forward-biased diode. 14. You have an unknown type of diode in a circuit. You measure the voltage across it and find it to be 0.3 V. The diode might be A. a silicon diode. B. a germanium diode. C. a forward-biased silicon diode. D. a reverse-biased germanium diode. 15. An ideal diode presents a(n) ________ when reversed-biased and a(n) ________ when forward-biased. A. open, short B. short, open C. open, open D. short, short

16. A reverse-biased diode has the ________ connected to the positive side of the source, and the ________ connected to the negative side of the source. A. cathode, anode B. cathode, base C. base, anode D. anode, cathode 17. What types of impurity atoms are added to increase the number of conduction-band electrons in intrinsic silicon? A. bivalent B. octavalent C. pentavalent D. trivalent E. none of the above 18. What factor(s) do(es) the barrier potential of a pn junction depend on? A. type of semiconductive material B. the amount of doping C. the temperature D. all of the above E. type of semiconductive material and the amount of doping but not the temperature 19. An atom is made up of A. protons. B. neutrons. C. electrons. D. all of the above 20. Reverse breakdown is a condition in which a diode A. is subjected to a large reverse voltage. B. is reverse-biased and there is a small leakage current. C. has no current flowing at all. D. is heated up by large amounts of current current in the forward direction. 21. There is a small amount of current across the barrier of a reverse-biased diode. This current is called A. forward-bias current. B. reverse breakdown current. C. conventional current. D. reverse leakage current. 22. As the forward current through a silicon diode increases, the voltage across the diode A. increases to a 0.7 V maximum. B. decreases.

INDIABIX ELECTRONICS

C. D.

is relatively constant. decreases and then increases.

23. Doping of a semiconductor material means A. that a glue-type substance is added to hold the material together. B. that impurities are added to increase the resistance of the material. C. that impurities are added to decrease the resistance of the material. D. that all impurities are removed to get pure silicon. 24. The forward voltage across a conducting silicon diode is about A. 0.3 V. B. 1.7 V. C. –0.7 V. D. 0.7 V. 25. The most common type of diode failure is a(n) ________. A. open B. short C. resistive 26. What occurs when a conductionband electron loses energy and falls back into a hole in the valence band? A. doping B. recombination C. generation 27. The maximum number of electrons in each shell of an atom is A. 2. 2 B. 2n where n is the number of the shell. C. 4. D. 8. 28. A silicon diode is forward-biased. You measure the voltage to ground from the anode at ________, and the voltage from the cathode to ground at ________. A. 0 V, 0.3 V B. 2.3 V, 1.6 V C. 1.6 V, 2.3 V D. 0.3 V, 0 V 29. The term bias in electronics usually means A. the value of ac voltage in the signal. B. the condition of current through a pn junction.

C.

D.

the value of dc voltages for the device to operate properly. the status of the diode.

SPECIAL- PURPOSE DIODES 1. Schottky diodes are also known as A. PIN diodes. B. hot carrier diodes. C. step-recovery diodes. D. tunnel diodes. 2. Zener diodes with breakdown voltages less than 5 V operate predominantly in what type of breakdown? A. avalanche B. zener C. varactor D. Schottky 3. The Schottky diode is used A. in high-power circuits. B. in circuits requiring negative resistance. C. in very fast-switching circuit D. in power supply rectifiers 4. You have an application for a diode to be used in a tuning circuit. A type of diode to use might be A. an LED. B. a Schottky diode. C. a Gunn diode. D. a varactor.

A. B. C.

increase. decrease. remain the same.

7. What kind of diode is formed by joining a doped semiconductor region with a metal? A. laser B. tunnel C. pin D. Schottky 8. Refer to this figure. Which symbol is correct for a zener diode?

A. B. C. D. E.

a b c d e

9. Which diode employs graded doping? A. zener B. LED C. tunnel D. step-recovery 10. Refer to this figure. Identify the Schottky diode.

5. Refer to this figure. Which symbol is correct for an LED?

A. B. C. D. E.

a b c d e

6. Refer to this figure. If V IN increases, IZ will

A. B. C. D. E.

a b c d e

11. LEDs are made out of A. silicon. B. germanium. C. gallium. D. silicon and germanium, but not gallium. 12. The normal operating region for a zener diode is the A. forward-bias region.

INDIABIX ELECTRONICS

B. C. D.

reverse-bias region. zero-crossing region. reverse-breakdown region.

13. Refer to this figure. If V IN attempts to increase, VR will

A. B. C.

increase. decrease. remain the same.

14. An LED is forward-biased. The diode should be on, but no light is showing. A possible trouble might be A. the diode is open. B. the series resistor is too small. C. none. The diode should be off if forward-biased. D. the power supply voltage is too high. 15. A 6.2 V zener is rated at 1 watt. The maximum safe current the zener can carry is A. 1.61 A. B. 161 mA. C. 16.1 mA. D. 1.61 mA. 16. Refer to this figure. Find the tunnel diode symbol.

A. B. C. D. E.

a b c d e

17. Refer to this figure. If the load l oad current increases, IR will _____ and I Z will _____.

18. The process of emitting photons from a semiconductive material is called A. photoluminescence. B. gallium arsenide. C. electroluminescence. D. gallium phosphide. 19. An 8.2 V zener has a resistance of 5Ω. The actual voltage across its terminals when the current is 25 mA is A. 8.2 V. B. 125 mV. C. 8.325 V. D. 8.075 V. 20. What diode operates only with majority carriers? A. laser B. tunnel C. Schottky D. step-recovery 21. Refer to this figure. Which symbol is correct for a photodiode?

A. B. C. D. E.

a b c d e

decrease. remain the same.

25. Zener diodes with breakdown voltages greater than 5 V operate predominantly in what type of breakdown? A. avalanche B. zener C. varactor D. Schottky 26. Back-to-back varactor diodes are used for what reason? A. over-voltage protection B. a wider tuning range C. to eliminate harmonic distortion D. no reason; only zeners are used in a back-to-back configuration 27. A tunnel diode is used A. in high-power circuits. B. in circuits requiring negative resistance. C. in very fast-switching circuits. D. in power supply rectifiers. 28. What type of diode is commonly used in electronic tuners in TVs? A. varactor B. Schottky C. LED D. Gunn

22. What type of diode maintains a constant current? A. LED B. zener C. current regulator D. pin E. none of the above

29. A laser diode normally emits A. coherent light. B. monochromatic light. C. coherent and monochromatic light. D. neither coherent nor monochromatic light.

23. What diode is used in seven-segment displays? A. zener B. LED C. laser D. Schottky

30. A varactor is a pn junction diode that always operates in ________-bias and is doped to ________ the inherent capacitance of the depletion region. A. forward, maximize B. reverse, maximize C. reverse, minimize D. forward, minimize

24. Refer to this figure. If V IN decreases, IR will

A. B. C. D.

B. C.

BIPOLAR JUNCTION TRANSISTORS

remain the same, increase decrease, remain the same increase, remain the same remain the same, decrease A.

increase.

1. Refer to this figure. Determine the minimum value of IB that will produce saturation.

INDIABIX ELECTRONICS

A. B. C. D.

A. B. C. D.

0.25 mA 5.325 µA 1.065 µA 10.425 µA

2. A transistor amplifier has a voltage gain of 100. If the input voltage is 75 mV, the output voltage is: A. 1.33 V B. 7.5 V C. 13.3 V D. 15 V 3. Refer to this figure. If V CE = 0.2 V, I C(sat) is:

9.2 V 9.9 V –9.9 V –9.2 V

7. When a transistor is used as a switch, it is stable in which two distinct regions? A. saturation and active B. active and cutoff C. saturation and cutoff D. none of the above 8. The term BJT is short for A. base junction transistor. B. binary junction transistor. C. both junction transistor. D. bipolar junction transistor 9. For a silicon transistor, when a baseemitter junction is forward-biased, it has a nominal voltage drop of A. 0.7 V. B. 0.3 V. C. 0.2 V. D. VCC.

14. Refer to this figure. The value of V BE is:

A. B. C. D.

0.6 V 0.7 V 1.2 V 0.079 V

15. What are the two types of bipolar junction transistors? A. npn and pnp B. pnn and nnp C. ppn and nnp D. pts and stp 16. In this circuit βDC= 100 and VIN = 8 V. The value of RB that will produce saturation is:

10. A certain transistor has I C = 15 mA and IB = 167µA; βDC is: A. 15 B. 167 C. 0.011 D. 90 A. B. C. D.

0.05 mA 2.085 mA 1.065 mA 7.4 mA

11. Refer to this figure. The value of V CE is:

4. What is the ratio of I C to IB? A. βDC B. hFE C. αDC D. either βDC or hFE, but not αDC 5. For normal operation of a pnp BJT, the base must be ________ with respect to the emitter and ________ with respect to the collector. A. positive, negative B. positive, positive C. negative, positive D. negative, negative 6. Refer to this figure. The value of V BC is:

A. B. C. D.

9.9 V 9.2 V 0.7 V 19.3 V

12. What does βDC vary with? A. IC B. ºC C. both IC and ºC D. IC , but not ºC 13. A BJT has an I B of 50µA and a βDC of 75; IC is: A. 375 mA B. 37.5 mA C. 3.75 mA D. 0.375 mA

A. B. C. D.

92 kΩ 9.1 MΩ 100 kΩ 150 kΩ

17. The value of βDC A. is fixed for any particular transistor. B. varies with temperature. C. varies with IC. D. varies with temperature and IC. 18. A transistor data sheet usually identifies βDC as A. hre. B. hFE. C. IC. D. VCE. 19. What is the ratio of I C to IE? A. βDC B. C.

D.

βDC / (βDC + 1) βDC either βDC / (βDC + 1) or αDC, but not βDC

INDIABIX ELECTRONICS

20. Refer to this figure. The value of βDC = 100 and VIN = 8 V. Determine I C(sat).

A. B. C. D.

18 mA 7.92 mA 1.8 mA 8 µA

21. Which of the following is true for an npn or pnp transistor? A. IE = IB + IC B. IB = IC+ IE C. IC = IB + IE D. none of the above

27. What is (are) common fault(s) in a BJT-based circuit? A. opens or shorts internal to the transistor B. open bias resistor(s) C. external opens and shorts on the circuit board D. all of the above 28. The dc load line on a family of collector characteristic curves of a transistor shows the A. saturation region. B. cutoff region. C. active region. D. all of the above 29. Refer to this figure. Determine the minimum value of VIN from the following that will saturate this transistor.

22. What is the order of doping, from heavily to lightly doped, for each region? A. base, collector, emitter B. emitter, collector, base C. emitter, base, collector D. collector, emitter, base 23. In what range of voltages is the transistor in the linear region of its operation? A. 0 < VCE B. 0.7 < VCE < VCE(max) C. VCE(max) > VCE D. none of the above 24. The magnitude of dark current in a phototransistor usually falls in what range? A. mA B. μA C. nA D. pA 25. A 35 mV signal is applied to the base of a properly biased transistor with an r'e = 8 and RC = 1 k. The output signal voltage at the collector is: A. 3.5 V B. 28.57 V C. 4.375 mV D. 4.375 V 26. What is (are) general-purpose/smallsignal transistors case type(s)? A. TO-18 B. TO-92 C. TO-39 D. TO-52 E. all of the above

A. B. C. D.

13.21 V 12.51 V 0.7 V 9.4 V

BJT DEVICES 1. How much is the base-to-emitter voltage of a transistor in the "on" state? A. 0V B. 0.7 V C. 0.7 mV D. Undefined 2. How many layers of material does a transistor have? A. 1 B. 2 C. 3 D. 4 3. Which of the following equipment can check the condition of a transistor? A. Current tracer B. Digital display meter (DDM) C. Ohmmeter (VOM) D. All of the above

4. For what kind of amplifications can the active region of the commonemitter configuration be used? A. Voltage B. Current C. Power D. All of the above 5. In the active region, while the collector-base junction is ________biased, the base-emitter is ________biased. A. forward, forward B. forward, reverse C. reverse, forward D. reverse, reverse 6. A transistor can be checked using a(n) ________. A. curve tracer B. digital meter C. ohmmeter D. Any of the above 7. What range of resistor values would you get when checking a transistor for forward- and reverse-biased conditions by an ohmmeter? A. 100 to a few kΩ, exceeding 100 kΩ B. Exceeding 100 kΩ, 100 to a few kΩ C. Exceeding 100 kΩ, exceeding 100 kΩ D. 100Ω to a few kΩ, 100Ω to a few kΩ 8. Calculate minority current I CO if IC = 20.002 mA and I C majority = 20 mA. A. 20 µA B. 0.002 µA C. 2 nA D. 2 µA 9. What is (are) the component(s) of electrical characteristics on the specification sheets? A. On B. Off C. Small-signal characteristics D. All of the above 10. In which region are both the collector-base and base-emitter junctions forward-biased? A. Active B. Cutoff C. Saturation D. All of the above

INDIABIX ELECTRONICS

11. An example of a pnp silicon transistor is a 2N4123. A. True B. False

A. B. C. D.

12. Which of the following is (are) the terminal(s) of a transistor? A. Emitter B. Base C. Collector D. All of the above

25. βdc for this set of collector characteristics is within ________ percent of βac.

13. Use this table of collector characteristics to calculate βac at VCE = 15 V and IB = 30 µA.

A. B. C. D.

100 106 50 400

A. B. C. D.

100 116 50 110

19. Which of the following can be obtained from the last scale factor of a curve tracer? A. hFE B. αdc C. αac D. βac 20. Calculate βac for IC = 15 mA and V CE = 5 V.

14. Which of the following configurations can a transistor set up? A. Common-base B. Common-emitter C. Common-collector D. All of the above 15. What does a reading of a large or small resistance in forward- and reversebiased conditions indicate when checking a transistor using an ohmmeter? A. Faulty device B. Good device C. Bad ohmmeter D. None of the above 16. Determine the value of α when β = 100. A. 1.01 B. 101 C. 0.99 D. Cannot be solved with the information provided

A. B. C. D.

200 180 220 None of the above

21. βdc = ________ A. IB / IE B. IC / IE C. IC / IB D. None of the above 22. How many carriers participate in the injection process of a unipolar device? A. 1 B. 2 C. 0 D. 3

17. Transistors are ________-terminal devices. A. 2 B. 3 C. 4 D. 5

23. What are the ranges of the ac input and output resistance for a commonbase configuration? A. 10Ω–100Ω , 50 kΩ –1 MΩ B. 50 kΩ –1 MΩ, 10 Ω – 100Ω C. 10 Ω–100 kΩ, 50 Ω –1 kΩ D. None of the above

18. Calculate βdc at VCE = 15 V and I B = 30 µA.

24. What is the most frequently encountered transistor configuration?

A. B. C. D.

Common-base Common-collector Common-emitter Emitter-collector

2 5 7 10

26. Which of the following regions is (are) part of the output characteristics of a transistor? A. Active B. Cutoff C. Saturation D. All of the above 27. How many individual pnp silicon transistors can be housed in a 14-pin plastic dual-in-line package? A. 4 B. 7 C. 10 D. 14 28. In what decade was the first transistor created? A. 1930s B. 1940s C. 1950s D. 1960s 29. Most specification sheets are broken down into ________. A. maximum ratings B. thermal characteristics C. electrical characteristics D. All of the above 30. For a properly biased pnp transistor, let IC = 10 mA and I E = 10.2 mA. What is the level of IB? A. 0.2 A B. 200 mA C. 200 µA D. 20.2 ma 31. What is (are) the component(s) of most specification sheets provided by the manufacturer?

INDIABIX ELECTRONICS

A. B. C. D.

Maximum ratings Thermal characteristics Electrical characteristics All of the above

32. What is βdc equal to? A. IB / IE B. IC / IE C. IC / IB D. None of the above 33. List the types of bipolar junction transistors. A. ppn, npn B. pnp, npn C. npp, ppn D. nnp, pnp 34. What is the ratio of the total width to that of the center layer for a transistor? A. 1:15 B. 1:150 C. 15:1 D. 150:1 35. Which component of the collector current IC is called the leakage current? A. Majority B. Independent C. Minority D. None of the above

10. What is the most important r parameter for amplifier analysis? A. rb′ B. rc′ C. re ′

A. B. C. D.

2 mA 4 mA 5 mA 6 mA

5. Which of the following is referred to as the reverse transfer voltage ratio? A. hi B. hr C. hf D. ho 6. Which of the following conditions must be met to allow the use of the approximate approach in a voltagedivider bias configuration? A. βre > 10R2 B. βre > 10R2 C. βre < 10R2 D. βre < 10R2

C.

β1/β2

D.

β1· (β2 -1)

2. Which of the following configurations has the lowest output impedance? A. Fixed-bias B. Voltage-divider C. Emitter-follower D. None of the above 3. Which of the h-parameters corresponds to re in a common-base configuration? A. hib B. hfb C. hrb D. hob 4. Refer to this figure. Find the value of IE.

13. Refer to this figure. Calculate the value of VB.

A. B. C. D.

1. The current gain for the Darlington connection is ________. A. β1· (β2 /2) β1· β2

12. The ________ model fails to account for the output impedance level of the device and the feedback effect from output to input. A. hybrid equivalent B. re C. β D. Thevenin

7. Refer to this figure. Determine the value of Av.

BJT AMPLIFIERS

B.

11. An emitter-follower is also known as: A. common-emitter amplifier. B. common-base amplifier. C. common-collector amplifier. D. Darlington pair.

A. B. C. D.

49.6 5 100 595

8. For a common-emitter amplifier, the purpose of swamping is A. to minimize gain. B. to reduce the effects of r'e C. to maximize gain. D. no purpose. 9. What is the typical value of the current gain of a common-base configuration? A. Less than 1 B. Between 1 and 50 C. Between 100 and 200 D. Undefined

5V 3.7 V 20 V 3V

14. You have a need to apply an amplifier with a very high power gain. Which of the following would you choose? A. common-collector B. common-base C. common-emitter D. emitter-follower 15. What is the voltage gain of a feedback pair connection? A. 1 B. –1 C. 100 D. –100 16. A common-emitter amplifier has ________ voltage gain, ________ current gain, ________ power gain, and ________ input impedance. A. high, low, high, low

INDIABIX ELECTRONICS

B. C. D.

high, high, high, low high, high, high, high low, low, low, high

17. What is the range of the input impedance of a common-base configuration? A. A few ohms to a maximum of 50 Ω B. 1 kΩ to 5 kΩ C. 100 kΩ to 500 kΩ D. 1 MΩ to 2 MΩ 18. The advantage that a Sziklai pair has over a Darlington pair is A. higher current gain. B. less input voltage is needed to turn it on. C. higher input impedance. D. higher voltage gain. 19. What is the typical range of the output impedance of a common-emitter configuration? A. 10Ω to 100Ω B. 1 kΩ to 5 kΩ C. 40 kΩ to 50 kΩ D. 500 kΩ to 1 kΩ 20. What is the unit of the parameter h o? A. Volt B. Ohm C. Siemen D. No unit 21. Refer to this figure. Calculate the value of Rin(tot).

A. B. C. D.

The output and input voltages are 180º out of phase. Gain is smaller than 1. Gain is larger than 1. None of the above

24. For the common-emitter fixed-bias configuration, there is a ________ phase shift between the input and output signals. A. 0º B. 45º C. 90º D. 180º 25. Which one of the following configurations has the lowest input impedance? A. Fixed-bias B. Common-base C. Emitter-follower D. Voltage-divider? 26. Which of the following represent(s) the advantage(s) of the system approach over the r-model approach? A. Thevenin's theorem can be used. B. The effect of changing the load can be determined by a simple equation. C. There is no need to go back to the ac equivalent model and analyze the entire network. D. All of the above 27. The differential amplifier has A. one input and one output. B. two inputs and two outputs. C. two inputs and one output. D. one input and two outputs.

A. B. C. D.

37.7 kΩ 3.77 kΩ 378 Ω 2.25 kΩ

22. What is the range of the current gain for BJT transistor amplifiers? A. less than 1 B. 1 to 100 C. above 100 D. All of the above 23. What does the negative sign in the voltage gain of the common-emitter fixed-bias configuration indicate?

28. The emitter-follower configuration has a ________ impedance at the input and a ________ impedance at the output. A. low, low B. low, high C. high, low D. high, high 29. The differential amplifier produces outputs that are A. common mode. B. in-phase with the input voltages. C. the sum of the two input voltages.

D.

the difference of the two input voltages.

30. The ________ model suffers from being limited to a particular set of operating conditions if it is to be considered accurate. A. hybrid equivalent B. re C. β D. Thevenin 31. Under which of the following condition(s) is the current gain A v ≈ β ? A. ro 10RC B. RB 10re C. ro 10RC and RB 10re D. None of the above 32. The ________ configuration is frequently used for impedance matching. A. fixed-bias B. voltage-divider bias C. emitter-follower D. collector feedback 33. Refer to this figure. You notice while servicing this amplifier that the output signal at Vout is reduced from normal. The problem could be caused by

A. B. C. D.

an open C3. an open C2. an open base-emitter of Q2. a shorted C2.

34. When the bypass capacitor is removed from a common-emitter amplifier, the voltage gain A. increases. B. decreases. C. has very little effect. 35. Refer to this figure. Determine the value of VC.

INDIABIX ELECTRONICS

46. In an un-bypassed emitter bias configuration hie replaces ________ in the re model. A. re B. β C. βre D. Ib

A. B. C. D.

20 V 10 V 5V 0V

36. In a common-base amplifier, the input signal is connected to the A. base. B. collector. C. emitter. D. output. 37. Which of the following is (are) true to achieve a good overall voltage gain for the circuit? A. The effect of R s and RL must be considered as a product. B. The effect of Rs and RL must be considered as a product and evaluated individually. C. The effect of R s and RL must be evaluated individually. D. None of the above 38. To analyze the common-emitter amplifier, what must be done to determine the dc equivalent circuit? A. leave circuit unchanged B. replace coupling and bypass capacitors with opens C. replace coupling and bypass capacitors with shorts D. replace VCC with ground 39. For the common-emitter amplifier ac equivalent circuit, all capacitors are A. effectively shorts. B. effectively open circuits. C. not connected to ground. D. connected to ground. 40. Refer to this figure. If an emitter bypass capacitor was installed, determine the value of R in(base).

A. B. C. D.

416 Ω 5 kΩ 50 kΩ 500 Ω

41. Under which of the following conditions is the output impedance of the network approximately equal to R C for a common-emitter fixed-bias configuration? A. ro 10RC B. ro < 10RC C. ro < ro D. ro > ro 42. Which of the following gains is less than 1 for a common-base configuration? A. Ai B. Av C. Ap D. None of the above 43. Which of the following define(s) the conversion efficiency? A. Ac power to the load/ac input power B. Ac power to the load/dc power supplied C. Dc output power/ac input power D. All of the above 44. The dc emitter current of a transistor is 8 mA. What is the value of r e? A. 320 Ω B. 13.3 kΩ C. 3.125 Ω D. 5.75 Ω 45. Which of the following should be done to obtain the ac equivalent of a network? A. Set all dc sources to zero B. Replace all capacitors by a short-circuit equivalent. C. Remove all elements bypassed by the short-circuit equivalent. D. All of the above

47. Which of the following is (are) true regarding the input impedance for frequencies in the midrange 100 kHz of a BJT transistor amplifier? A. The input impedance is purely resistive. B. It varies from a few ohms to megohms. C. An ohmmeter cannot be used to measure the smallsignal ac input impedance. D. All of the above 48. For the collector dc feedback configuration, there is a ________ phase shift between the input and output signals. A. 0º B. 45º C. 90º D. 180º 49. A common-collector amplifier has ________ input resistance, ________ current gain, and ________ voltage gain. A. high, high, low B. high, low, low C. high, low, high 50. The total gain of a multistage amplifier is the ________. A. sum of individual voltage gains B. sum of dB voltage gains 51. Which of the following configurations has an output impedance Zo equal to RC? A. Fixed-bias common-emitter B. Common-emitter voltagedivider with bypass capacitor C. Common-emitter voltagedivider without bypass capacitor D. All of the above 52. Refer to this figure. Find the value of Rin(base).

INDIABIX ELECTRONICS

A. B. C. D.

420 Ω 50 kΩ 940 Ω 100.8 Ω

53. For a common-emitter amplifier, the purpose of the emitter bypass capacitor is A. no purpose, since it is shorted out by RE. B. to reduce noise. C. to despike the supply voltage. D. to maximize amplifier gain. 54. For BJT amplifiers, the ________ gain typically ranges from a level just less than 1 to a level that may exceed 1000. A. voltage B. current C. impedance D. All of the above 55. The loaded voltage gain of an amplifier is always more than the noload level. A. True B. False 56. Which of the following configurations has a voltage gain of –RC /re? A. Fixed-bias common-emitter B. Common-emitter voltagedivider with bypass capacitor C. Fixed-bias common-emitter and voltage-divider with bypass capacitor D. Common-emitter voltagedivider without bypass capacitor 57. An emitter-follower amplifier has an input impedance of 107 kΩ. The input signal is 12 mV. The approximate output voltage is (common-collector) A. 8.92 V B. 112 mV C. 12 mV D. 8.9 mV

58. Which of the following is (are) true regarding the output impedance for frequencies in the midrange 100 kHz of a BJT transistor amplifier? A. The output impedance is purely resistive. B. It varies from a few ohms to more than 2 MΩ. C. An ohmmeter cannot be used to measure the smallsignal ac output impedance. D. All of the above 59. Refer to this figure. The output signal from the first stage of this amplifier is 0 V. The trouble could be caused by

64. The input impedance of a BJT amplifier is purely ________ in nature and can vary from a few ________ to ________. A. resistive, ohms, megohms B. capacitive, microfarads, farads C. inductive, millihenrys, henrys D. None of the above 65. The ________ the source resistance and/or ________ the load resistance, the less the overall gain of an amplifier. A. smaller, smaller B. smaller, larger C. larger, smaller D. larger, larger 66. Refer to this figure. If an emitter bypass capacitor was installed, what would the new A v be?

A. B. C. D.

an open C4. an open C2. an open base-emitter of Q1. a shorted C4.

60. What is the limit of the efficiency defined by = Po / Pi? A. Greater than 1 B. Less than 1 C. Always 1 D. None of the above 61. What is re equal to in terms of h parameters? A. hre / hoe B. (hre + 1) / hoe C. hie – (hre / hoe)(1 + hfe) D. hfe E. none of the above 62. What is the controlling current in a common-base configuration? A. Ie B. Ic C. Ib D. None of the above 63. Which of the following techniques can be used in the sinusoidal ac analysis of transistor networks? A. Small-signal B. Large-signal C. Small- or large-signal D. None of the above

A. B. C. D.

4.96 125 398 600

67. A Darlington pair provides beta ________ for ________ input resistance. A. multiplication, decreased B. multiplication, increased C. division, decreased 68. A Darlington pair amplifier has A. high input impedance and high voltage gain. B. low input impedance and low voltage gain. C. a voltage gain of about 1 and a low input impedance. D. a low voltage gain and a high input impedance.

FET DEVICES 1. Which of the following ratings appear(s) in the specification sheet for an FET? A. Voltages between specific terminals B. Current levels

INDIABIX ELECTRONICS

C. D.

Power dissipation All of the above

2. What is the level of drain current ID for gate-to-source voltages VGS less than (more negative than) the pinch-off level? A. zero amperes B. IDSS C. Negative value D. Undefined 3. What is the level of I G in an FET? A. Zero amperes B. Equal to ID C. Depends on VDS D. Undefined 4. What is the range of an FET's input impedance? A. 10Ω to 1 kΩ B. 1 kΩ to 10 kΩ C. 50 kΩ to 100 kΩ D. 1 MΩ to several hundred MΩ 5. Which of the following applies to a safe MOSFET handling? A. Always pick up the transistor by the casing. B. Power should always be off when network changes are made. C. Always touch ground before handling the device. D. All of the above 6. Refer to this portion of a specification sheet. Determine the values of reversegate-source voltage and gate current if the FET was forced to accept it.

A. B. C. D.

0.25 0.5 1 0

9. Referring to this transfer curve, determine I D at VGS = 2 V.

14. The drain current will always be onefourth of I DSS as long as the gate-tosource voltage is ________ the pinch-off value. A. one-fourth B. one-half C. three-fourths D. None of the above 15. The transfer curve is not defined by Shockley's equation for the ________. A. JFET B. depletion-type MOSFET C. enhancement-type MOSFET D. BJT

A. B. C. D.

0.444 mA 1.333 mA 0.111 mA 4.444 mA

16. What is the purpose of adding two Zener diodes to the MOSFET in this figure?

10. Which of the following controls the level of ID? A. VGS B. VDS C. IG D. VDG 11. It is the insulating layer of ________ in the MOSFET construction that accounts for the very desirable high input impedance of the device. A. SiO B. GaAs C. SiO2 D. HCl 12. The BJT is a ________ device. The FET is a ________ device. A. bipolar, bipolar B. bipolar, unipolar C. unipolar, bipolar D. unipolar, unipolar

A. B. C. D.

To reduce the input impedance To protect the MOSFET for both polarities To increase the input impedance None of the above

17. Referring to the following transfer curve, determine the level of V GS when the drain current is 20 mA.

13. Referring to this transfer curve. Calculate (using Shockley's equation) VGS at ID = 4mA. A. B. C. D.

25 Vdc, –200 nAdc –25 Vdc, 10 mAdc –6 Vdc, –1.0 nAdc None of the above

7. At which of the following condition(s) is the depletion region uniform? A. No bias B. VDS > 0 V C. VDS = VP D. None of the above 8. What is the ratio of ID / IDSS for VGS = 0.5 V P?

A. B. C. D.

A. B. C. D.

2.54 V –2.54 V –12 V Undefined

1.66 V –1.66 V 0.66 V –0.66 V

18. The region to the left of the pinch-off locus is referred to as the ________ region. A. saturation B. cutoff

INDIABIX ELECTRONICS

C. D.

ohmic All of the above

19. Refer to the following curves. Calculate ID at VGS = 1 V.

A. B. C. D.

2 3 4 3 or 4

25. Refer to the following figure. Calculate VGS at I D = 8 mA for k = 0.278 × –2 2 10 A/V .

A. B. C. D.

A. B. C. D.

8.167 mA 4.167 mA 6.167 mA 0.616 mA

20. Which of the following transistor(s) has (have) depletion and enhancement types? A. BJT B. JFET C. MOSFET D. None of the above 21. The three terminals of the JFET are the ________, ________, and ________. A. gate, collector, emitter B. base, collector, emitter C. gate, drain, source D. gate, drain, emitter 22. Which of the following is (are) the terminal(s) of a field-effect transistor (FET). A. Drain B. Gate C. Source D. All of the above 23. A BJT is a ________-controlled device. The JFET is a ________ controlled device. A. voltage, voltage B. voltage, current C. current, voltage D. current, current 24. How many terminals can a MOSFET have?

3.70 V 5.36 V 7.36 V 2.36 V

26. The level of V GS that results in I D = 0 mA is defined by V GS = ________. A. VGS(off) B. VP C. VDS D. None of the above 27. Which of the following FETs has the lowest input impedance? A. JFET B. MOSFET depletion-type C. MOSFET enhancement-type D. None of the above 28. Which of the following applies to MOSFETs? A. No direct electrical connection between the gate terminal and the channel B. Desirable high input impedance C. Uses metal for the gate, drain, and source connections D. All of the above 29. At which of the following is the level of VDS equal to the pinch-off voltage? A. When ID becomes equal to I DSS B. When VGS is zero volts C. IG is zero D. All of the above 30. Which of the following represent(s) the cutoff region for an FET? A. ID = 0 mA B. VGS = VP C. IG = 0 D. All of the above 31. Which of the following is (are) the advantage(s) of VMOS over MOSFETs?

A. B. C. D.

Reduced channel resistance Higher current and power ratings Faster switching time All of the above

32. Hand-held instruments are available to measure ________ for the BJT. A. βDC B. IDSS C. VP D. All of the above 33. Which of the following input impedances is not valid for a JFET? 10 A. 10 Ω 9 B. 10 Ω 8 C. 10 Ω 11 D. 10 Ω 34. Refer to the following characteristic curve. Calculate the resistance of the FET at VGS = –0.25 V if r o = 10 kΩ.

A. B. C. D.

1.1378 kΩ 113.78 Ω 11.378 Ω 11.378 kΩ

35. Which of the following is (are) not an FET? A. n-channel B. p-channel C. p-n channel D. n-channel and p-channel

FET AMPLIFIERS 1. A common-gate amplifier is similar in configuration to which BJT amplifier? A. common-emitter B. common-collector C. common-base D. emitter-follower 2. The theoretical efficiency of a class D amplifier is A. 75%. B. 85%. C. 90%. D. 100%.

INDIABIX ELECTRONICS

3. A common-source amplifier is similar in configuration to which BJT amplifier? A. common-base B. common-collector C. common-emitter D. emitter-follower

A. B. C. D.

common-emitter common-collector common-base common-gate

9. Referring to this figure, calculate A v for yos = 58µS.

4. Refer to this figure. If R 6 opened, the signal at the drain of Q 1 would A. B. C. D. A. B. C. D.

increase. decrease. remain the same. distort.

5. Refer to this figure. Find the value of VD.

14. Referring to the following figure, calculate gm for VGSQ = –1.25 V. A. B. C. D.

–7.29 –7.50 –8.05 –8.55

10. Refer to this figure. If V in = 1 V p-p , the output voltage Vout would be A. B. C. D.

A. B. C. D.

20 V 11 V 10 V 9V

6. A BJT is a ________-controlled device. A. current B. voltage 7. Referring to this figure, calculate A v if rd = 19 kΩ.

–2.85 –3.26 –2.95 –3.21

8. A common-drain amplifier is similar in configuration to which BJT amplifier?

2 mS 2.5 mS 2.75 mS 3.25 mS

15. Referring to this figure, calculate the value of RD if the ac gain is 10. Assume VGSQ = ¼Vp. A. B. C. D.

undistorted. clipped on the negative peaks. clipped on the positive peaks. 0 Vp-p

11. Use the following equation to calculate gm for a JFET having IDSS = 10 mA, VP = –5 V, and VGSQ = –2.5 V.

  || [  ] A. B. C. D.

A. B. C. D.

176 mV p-p 88 mV p-p 48 mV p-p 24 mV p-p

A. B. C. D.

2 mS 3 mS 4 mS 5 mS

12. For what value of I D is gm equal to 0.5 gm0? A. 0 mA B. 0.25 IDSS C. 0.5 IDSS D. IDSS 13. Refer to this figure. If V in = 20 mV what is the output voltage?

p-p

2.2 kΩ 2.42 kΩ 2.62 kΩ 2.82 kΩ

16. Where do you get the level of g m and rd for an FET transistor? A. from the dc biasing arrangement B. from the specification sheet C. from the characteristics D. All of the above 17. The class D amplifier uses what type of transistors? A. JFETs

INDIABIX ELECTRONICS

B. C. D.

BJTs MOSFETs any of the above

18. What is (are) the function(s) of the coupling capacitors C1 and C2 in an FET circuit? A. to create an open circuit for dc analysis B. to isolate the dc biasing arrangement from the applied signal and load C. to create a short-circuit equivalent for ac analysis D. All of the above 19. An FET is a ________-controlled device. A. current B. voltage 20. What is the input resistance (Rin(source)) of a common-gate amplifier? A. Rs B. (1+ gm) || Rs C. 1 / gm D. none of the above 21. There is a ________º phase inversion between gate and source in a source follower. A. 0 B. 90 C. 180 D. none of the above 22. Refer to this figure. If C 4 opened, the signal voltage at the drain of Q 1 would

A. B. C. D.

24. Which of the following is a required condition to simplify the equations for Zo and Av for the self-bias configuration? A. rd ≤10RD B. rd = RD C. rd ≥ 10RD D. None of the above 25. The steeper the slope of the I D versus VGS curve, the ________ the level of g m. A. less B. same C. greater 26. What is the typical value for the input impedance Z i for JFETs? A. 100 kΩ B. 1 MΩ C. 10 MΩ

D.

increase. decrease. remain the same. distort.

23. Referring to this figure, find Z o if y os = 20µS.

A. B. C. D.

2 mS 3 mS 4 mS 5 mS

31. Which type of FETs can operate with a gate-to-source Q-point value of 0 V? A. JFET B. E-MOSFET C. D-MOSFET 32. On which of the following parameters does rd have no or little impact in a source-follower configuration? A. Zi B. Zo C. Av @ D. All of the above 33. Refer to this figure. For midpoint biasing, ID would be

1000 MΩ

27. MOSFETs make better power switches than BJTs because they have A. lower turn-off times. B. lower on-state resistance. C. a positive temperature coefficient.

D.

A. B. C. D.

1.85 kΩ 1.92 kΩ 2.05 kΩ 2.15 kΩ

all of the above

28. When VGS = 0.5 Vp gm is ________ the maximum value. A. one-fourth B. one-half C. three-fourths 29. MOSFET digital switching is used to produce which digital gates? A. inverters B. NOR gates C. NAND gates D. all of the above 30. Referring to the transfer characteristics shown below, calculate gm at VGSQ = –1 V.

A. B. C. D.

10 mA. 7.5 mA. 5 mA. 2.5 mA.

34. Class D amplifiers differ from all

other classes of amplifiers because A. the output transistors are operated as switches. B. of their very low input capacitance. C. of their high-frequency response capabilities. D. they employ dual MOSFETs

INDIABIX ELECTRONICS

35. Refer to this figure. If R 7 were to decrease in value, Vout would

A. B. C. D.

100 kΩ 80 kΩ 25 kΩ 5 kΩ

40. Referring to this figure, calculate Z o if rd = 19 kΩ.

A. B. C. D.

A. B. C. D.

increase. decrease. remain the same. distort

36. Refer to this figure. If I D = 4 mA, find the value of VGS.

A. B. C. D.

1.75 kΩ 1.81 kΩ 1.92 kΩ 2.00 kΩ

41. Referring to this figure, calculate Z i if rd = 19 kΩ.

A. B. C. D.

362.52 Ω 340.5 Ω 420.5 Ω 480.9 Ω

45. The more horizontal the characteristic curves on the drain characteristics, the ________ the output impedance. A. less B. same C. greater 46. Refer to this figure. If g m = 4000 mS and a signal of 75 mV rms is applied to the gate, calculate the p-p output voltage.

10.8 V 6V –0.7 V –6 V

37. Which FET amplifier(s) has (have) a phase inversion between input and output signals? A. common-gate B. common-drain C. common-source D. all of the above 38. What common factor determines the voltage gain and input resistance of a common-gate amplifier? A. RD B. RL C. gm

A. B. C. D.

2.42 MΩ 2.50 MΩ 2.53 MΩ 2.59 MΩ

42. For the fixed-bias configuration, if r D < 10 RD , then Zo = ________. A. RD B. RD || rD C. RG D. -gm · (RD || rD )

A. B. C. D.

990 mV 1.13 V p-p 2.8 V p-p 990 V p-p

47. Refer to this figure. The approximate value of Rin is

43. Referring to this figure, obtain g m for ID = 6 mA.

39. Referring to the figure below, determine the output impedance for V GS = –3 V at VDS = 5 V.

A. B. C. D.

2.83 mS 3.00 mS 3.25 mS 3.46 mS

44. Referring to this figure, calculate Z o for VGSQ = –3.2 V.

A. B. C. D.

100 MΩ. 1.5 kΩ. 3.3 kΩ. 48 MΩ.

48. Which of the following is (are) related to depletion-type MOSFETs? A. VGSQ can be negative, zero, or positive.

INDIABIX ELECTRONICS

B. C. D.

gm can be greater or smaller than gm0. ID can be larger than I DSS. All of the above

49. Refer to this figure. If C 2 shorted, Vout would

A. B. C. D.

increase. decrease. remain the same. distort.

50. The input resistance at the gate of a FET is extremely A. high. B. low. 51. Determine the value for R D if the ac gain is 8.

A. B. C. D.

1.51 kΩ 1.65 kΩ 1.85 kΩ 2.08 kΩ

52. Referring to this figure, calculate Z i for yos = 20 µS. Assume V GSQ = −2.2V.

B. C. D.

high input impedance low power consumption All of the above

54. CMOS digital switches use A. n-channel and p-channel MOSFETs in series. B. n-channel and p-channel MOSFETs in parallel. C. n-channel and p-channel MOSFETs in series. D. n-channel and p-channel MOSFETs in parallel.

DDEE-

55. What is the range of g m for JFETs? A. 1 µS to 10µS B. 100µS to 1000 µS C. 1000 µS to 5000 µS D. 10000 µS to 100000 µS 56. Calculate gm and rd if y fs = 4 mS and yos = 15ΩS. A. 4 mS, 66.7 kΩ B. 4 mS, 15 kΩ C. 66.7 kΩ, 4 mS D. None of the above 57. What limits the signal amplitude in an analog MOSFET switch? A. the switch input capacitance B. VGS(th) C. the switch's power handling D. VDS 58. Input resistance of a common-drain amplifier is A. RG || RIN(gate). B. RG + RIN(gate). C. RG. D. RIN(gate). 59. Refer to this Figure. If V in was increased in amplitude a little, the signal voltage at the source of Q2 would

A. B. C. D.

2.2 kΩ 1.2 kΩ 600 kΩ 100 kΩ

61. A JFET cascade amplifier employs A. 2 common-gate amplifiers. B. 2 common-source amplifiers. C. 1 common-gate and 1 common-source amplifier. D. 1 common-gate and 1 commondrain amplifier. 62. E-MOSFETs are generally used in switching applications because A. of their very low input capacitance. B. of their threshold characteristic (VGS(th)). C. of their high-frequency response capabilities. D. of their power handling. 63. For an FET small-signal amplifier, one could go about troubleshooting a circuit by ________. A. viewing the circuit board for poor solder joints B. using a dc meter C. applying a test ac signal D. All of the above 64. The E-MOSFET is quite popular in ________ applications. A. digital circuitry B. high-frequency C. buffering D. All of the above 65. Referring to this figure, calculate A v if yos = 20 µS.

A. B. C. D.

300.2 Ω 330.4 Ω 340.5 Ω 350.0 Ω

53. FET amplifiers provide ________. A. excellent voltage gain

A. B. C. D.

increase. decrease. remain the same. distort.

60. Refer to this figure. If V GS = –6 V, calculate the value of RS that will provide this value.

INDIABIX ELECTRONICS

A. B. C. D.

–3.48 –3.56 –3.62 –4.02

66. Referring to this figure, calculate Z o if yos = 40µS.

A. B. C. D.

19.2 V –6 V 10.8 V 30 V

70. If ID = IDSS / 2, gm = ________ gmo. A. 1 B. 0.707 C. 0.5

BJT AND FET FREQUENCY RESPONSE A. B. C. D.

2.92 kΩ 3.20 kΩ 3.25 kΩ 3.75 kΩ

67. In a common-source amplifier, the purpose of the bypass capacitor, C2, is to A. keep the source effectively at ac ground. B. provide a dc path to ground. C. provide coupling to the input. D. provide coupling to the load. 68. Refer to this figure. The voltage gain is

A. B. C. D.

1.2. 2.4. 4.4. 8.8.

1. A change in frequency by a factor of ________ is equivalent to 1 octave. A. 2 B. 10 C. 5 D. 20 2. What is the ratio of the capacitive reactance XCS to the input resistance R I of the input RC circuit of a single-stage BJT amplifier at the low-frequency cutoff? A. 0.25 B. 0.50 C. 0.75 D. 1.0

B. C. D.

46.13 Hz 238.73 Hz 1575.8 Hz

5. The smaller capacitive elements of the design will determine the ________ cutoff frequencies. A. low B. mid C. high 6. What is the range of the capacitor C ds? A. 0.01 to 0.1 pF B. 0.1 to 1 pF C. 0.1 to 1 nF D. 0.1 to 1 F 7. An amplifier rated at 30-W output is connected to a 5- speaker. Calculate the input voltage for the rated output if the amplifier voltage gain is 20 dB. A. 1.225 mV B. 12.25 mV C. 122.5 mV D. 1.225 V 8. A 3-dB drop in h fe will occur at a frequency defined by ________. A. f α B. f β C. 1 D. 2

3. For which of the following frequency region(s) can the coupling and bypass capacitors no longer be replaced by the short-circuit approximation? A. Low-frequency B. Mid-frequency C. High-frequency D. All of the above

9. An amplifier rated at 30-W output is connected to a 5- speaker. Calculate the input power required for full power output if the power gain is 20 dB. A. 3 mW B. 30 mW C. 300 mW D. 3W

4. Determine the lower cutoff frequency of this network.

10. The larger capacitive elements of the design will determine the ________ cutoff frequency. A. low B. mid C. high

69. Refer to this figure. If I D = 4 mA, IDSS = 16 mA, and VGS(off) = –8 V, find VDS.

11. Which of the following elements is (are) important in determining the gain of the system in the high-frequency region? A. Interelectrode capacitances B. Wiring capacitances C. Miller effect capacitance D. All of the above

A.

15.8 Hz

12. The input power to a device is 10,000 W at 1000 V. The output power is 500 W, and the output impedance is 100Ω. Find the voltage gain in decibels.

INDIABIX ELECTRONICS

A. B. C. D.

–30.01 dB –20.0 dB –13.01 dB –3.01 dB

13. By what factor does an audio level change if the power level changes from 4 W to 4096 W? A. 2 B. 4 C. 6 D. 8 14. For audio systems, the reference level is generally accepted as ________. A. 1 mW B. 1W C. 10 mW D. 100 mW 15. What is the range of the capacitors Cgs and Cgd? A. 1 to 10 pF B. 1 to 10 nF C. 1 to 10 F D. 1 to 10 F 16. For the low-frequency response of a BJT amplifier, the maximum gain is where ________ . A. RB = 0 Ω B. RC = 0 Ω C. RE = 0 Ω 17. In the input RC circuit of a singlestage BJT, by how much does the base voltage lead the input voltage at the cutoff frequency in the low-frequency region? A. About 0º B. 45º C. About 90º D. None of the above 18. What is the normalized gain expressed in dB for the cutoff frequencies? A. –3 dB B. +3 dB C. –6 dB D. –20 dB 19. Which of the low-frequency cutoffs determined by C S, CC, or CE will be the predominant factor in determining the low-frequency response for the complete system? A. lowest B. middle C. highest D. None of the above

20. Determine the break frequency for this circuit.

A. B. C. D.

15.915 Hz 159.15 Hz 31.85 Hz 318.5 Hz

21. What is the ratio of the common logarithm of a number to its natural logarithm? A. 0.435 B. 2 C. 2.3 D. 3.2 22. Which of the following configurations does (do) not involve the Miller effect capacitance? A. Common-emitter B. Common-base C. Common-collector D. All of the above 23. What magnitude voltage gain corresponds to a decibel gain of 50? A. 31.6238 B. 316.228 C. 3162.38 D. 31623.8

27. In the hybrid π or Giacolet to model, which one of the following does r b include? A. Base spreading resistance B. Base contact C. Base bulk D. All of the above 28. What is the ratio of the output voltage to the input voltage at the cutoff frequencies in a normalized frequency response plot? A. 0.25 B. 0.50 C. 0.707 D. 1 29. Which of the following statements is true for a square-wave signal? A. It is composed of both even and odd harmonics. B. It is composed only of odd harmonics. C. It is composed only of even harmonics. D. The harmonics waveforms are also square waves. 30. A change in frequency by a factor of ________ is equivalent to 1 decade. A. 2 B. 10 C. 5 D. 20

24. By what other name(s) are the cutoff frequencies in a frequency response plot called? A. Corner frequency B. Break frequency C. Half-power frequency D. All of the above

31. Which of the following capacitors is (are) included in Ci for the highfrequency region of a BJT or FET amplifier? A. Input wiring capacitance Cw1 B. The transition capacitance (Cbe / Cqs) C. Miller capacitance CM1 D. All of the above

25. The ________-frequency response of a transformer-coupled system is calculated primarily by the stray capacitance between the turns of the primary and secondary windings. A. low B. mid C. high

32. In the input RC circuit of a singlestage BJT, by how much does the base voltage lead the input voltage for frequencies much larger than the cutoff frequency in the low-frequency region? A. About 0º B. 45º C. About 90º D. None of the above

26. logea = ________ log10a A. 2.3 B. 2.718 C. e D. 1.414

33. In the ________-frequency region, the capacitive elements of importance are the interelectrode (between terminals) capacitances internal to the active device and the wiring capacitance between the leads of the network.

INDIABIX ELECTRONICS

A. B. C.

low mid high

34. What is the ratio of the output power to the input power at the cutoff frequencies in a normalized frequency response plot? A. 0.25 B. 0.50 C. 0.707 D. 1

BASIC OP AMP CIRCUITS 1. A Schmitt trigger is A. a comparator with only one trigger point. B. a comparator with hysteresis. C. a comparator with three trigger points. D. none of the above. 2. Refer to the given figure. This circuit is known as

A. B. C. D.

a noninverting amplifier. a differentiator. an integrator. a summing amplifier.

3. The output of a Schmitt trigger is a A. pulse waveform. B. sawtooth waveform. C. sinusoidal waveform. D. triangle waveform.

The output voltage is most likely to be

C. D.

summing amplifier comparator

11. Refer to the given figure. If V in = 5 V, the rate of change of the output voltage in response to a single pulse input is:

A. B. C. D.

a square wave. a triangle wave. a sine wave. no output.

6. Refer to the given figure. What is the output voltage?

A. B. C. D.

2V –2 V +Vsat –Vsat

7. If an op-amp comparator has a gain of 100,000, an input difference of 0.2 mV above reference, and a supply of ± 12 V, the output will be A. 20 V. B. 12 V. C. 10 V. D. 15 V. 8. A comparator with a Schmitt trigger has A. two trigger levels. B. a fast response. C. a slow response. D. one trigger level. 9. Refer to the given figure. Determine the upper trigger point.

A. B. C. D.

15.2 mV/μs 1.52 V/μs 1.52 mV/μs 15.2 V/μs

12. In a flash A/D converter, the priority encoder is used to A. select the first input. B. select the highest value input. C. select the lowest value input. D. select the last input. 13. What circuit produces an output that approximates the area under the curve of an input function? A. integrator B. differentiator C. summing amplifier D. comparator 14. An op-amp has an open-loop gain of 90,000. Vsat = ±13 V. A differential voltage of 0.1 Vp-p is applied between the inputs. What is the output voltage? A. 13 V B. –13 V C. 13 Vp-p D. 26 Vp-p 15. Refer to the given figure. Determine the output voltage.

4. Refer to the given figure. This circuit is known as

A. B. C. D.

a noninverting amplifier. a differentiator. an integrator. a summing amplifier.

5. Refer to the given figure. A squarewave input is applied to this amplifier.

A. B. C. D.

V(out)max –V(out)max –1.41 V +1.41 V

10. In a(n) ________, when the input voltage exceeds a specified reference voltage, the output changes state. A. integrator B. differentiator

A. B. C. D.

1V –1 V +Vsat –Vsat

16. A good example of hysteresis is a(n) A. AM radio. B. thermostat. C. alarm clock. D. none of the above

INDIABIX ELECTRONICS

17. To reduce the effects of noise resulting in erratic switching of output states of a comparator, you can use A. the upper trigger point. B. the lower trigger point. C. nonzero-level detection. D. hysteresis. 18. Refer to the given figure. With the inputs shown, determine the output voltage.

A. B. C. D.

summer nonzero-level detector averaging amplifier summer and nonzero-level detector

23. A differentiator is used to measure A. the sum of the input voltages. B. the difference between two voltages. C. the area under a curve. D. the rate of change of the input voltage. 24. Refer to the given figure. Determine the lower trigger point.

A. B. C. D.

A. B. C. D.

1.05 V –0.35 V 0.35 V –1.05 V

20. What is (are) the necessary component(s) for the design of a bounded comparator? A. rectifier diodes B. zener diodes C. both of the above 21. Refer to the given figure. What is the output voltage?

A. B. C. D.

0.5 V –0.5 V 2V –2 V

22. What type(s) of circuit(s) use comparators?

junction zener varactor

29. A comparator with hysteresis is sometimes known as a(n) A. integrator. B. differentiator. C. Schmitt trigger. D. none of the above 30. Which of the following are variations of the basic summing amplifier? A. averaging amplifier B. scaling amplifier C. both of the above

SEMICONDUCTOR DIODES

7V –7 V +Vsat –Vsat

19. Refer to the given figure. Determine the output voltage, VOUT.

B. C. D.

A. B. C. D.

+V(out)max –V(out)max –2.47 V +2.47 V

25. A(n) ________ amplifier is a summing amplifier with a closed-loop gain equal to the reciprocal of the number of inputs. A. averaging B. scaling C. none of the above 26. ________ is a mathematical process for determining the rate of change of a function. A. Integration B. Differentiation C. Summing D. Comparatoring 27. An integrator circuit A. uses a resistor in its feedback circuit. B. uses an inductor in its feedback circuit. C. uses a capacitor in its feedback circuit. D. uses a resistor in its feedback circuit or uses a capacitor in its feedback circuit 28. In a comparator with output bounding, what type of diode is used in the feedback loop? A. Schottky

1. One eV is equal to ________ J. A. 6.02 × 1023 –19 B. 1.6 × 10 18 C. 6.25 × 10 –24 D. 1.66 × 10 2. The diode ________. A. is the simplest of semiconductor devices B. has characteristics that closely match those of a simple switch C. is a two-terminal device D. All of the above 3. It is not uncommon for a germanium diode with an Is in the order of 1–2 µA at 25°C to have leakage current of 0.1 mA at a temperature of 100°C. A. True B. False 4. What does a high resistance reading in both forwardand reverse-bias directions indicate? A. A good diode B. An open diode C. A shorted diode D. A defective ohmmeter 5. Which capacitance dominates in the reverse-bias region? A. depletion B. conversion C. 40 Ω Diffusion D. 140 Ω None of the above 6. What is the state of an ideal diode in the region of nonconduction? A. An open circuit B. A short circuit C. Unpredictable

INDIABIX ELECTRONICS

D.

Undefined

7. How many orbiting electrons does the germanium atom have? A. 4 B. 14 C. 32 D. 41 8. How have? A. B. C. D.

many terminals does a diode 1 2 3 4

15. Which of the following devices can check the condition of a semiconductor diode? A. Digital display meter (DDM) B. Multimeter C. Curve tracer D. All of the above 16. Which of the following is an atom composed of? A. Electrons B. Protons C. Neutrons D. All of the above

9. What unit is used to represent the level of a diode forward current IF? A. pA B. nA C. µA D. mA

17. The condition of a semiconductor diode can be determined quickly using a ________. A. DDM B. VOM C. curve tracer D. Any of the above

10. The diffused impurities with ________ valence electrons are called donor atoms. A. 4 B. 3 C. 5 D. 0

18. How many valence electrons does a silicon atom have? A. 1 B. 2 C. 3 D. 4

11. In which of the following color(s) is (are) LEDs presently available? A. Yellow B. White C. Orange D. All of the above 12. Determining rd to a high degree of accuracy from a characteristic curve is very accurate. A. True B. False 13. What is the range of the operating voltage level for LEDs? A. 5–12 mV B. 1.7–3.3 V C. 5–12 V D. 20–25 V 14. At what kind of operating frequency diffusion or transition is a capacitor represented in parallel with the ideal diode? A. Low frequency B. Moderate frequency C. Mid frequency D. Very high frequency

19. What is the resistor value of an ideal diode in the region of conduction? A. 0Ω B. 5kΩ C. Undefined D. Infinity 20. Calculate the power dissipation of a diode having ID = 40 mA. A. 28 mW B. 28 W C. 280 mW D. Undefined 21. Calculate static resistance R D of a diode having ID = 30 mA and V D = 0.75 V. A. 25 B. 40 C. 0.04 D. 0.025 22. In which of the following is the light intensity measured? A. Candela B. Efficacy C. Flux D. Illumination 23. Calculate ID if RD = 30 and V D = 0.84 V. A. 28 mA B. 0.028 mA C. 2.8 A

D.

280 A

24. Which of the following elements is most frequently used for doping pure Ge or Si? A. Boron B. Gallium C. Indium D. All of the above 25. Calculate the temperature coefficient in %/° C of a 10-V nominal Zener diode at 25° C if the nominal voltage is 10.2 V at 100° C. A. 0.0238 B. 0.0251 C. 0.0267 D. 0.0321 26. In general, LEDs operate at voltage levels from ________ V to ________ V. A. 1.0, 3.0 B. 1.7, 3.3 C. 0.5, 4.0 D. None of the above 27. Determine the nominal voltage for the Zener diode at a temperature of 120° C if the nominal voltage is 5.1 volts at 25° C and the temperature coefficient is 0.05%/° C. A. 4.6 V B. 4.86 V C. 5.1 V D. 5.34 V 28. What is the maximum power rating for LEDs? A. 150 mW B. 500 mW C. 1W D. 10 W 29. The ________ diode model is employed most frequently in the analysis of electronic systems. A. ideal device B. simplified C. piecewise-linear 30. What is the value of the transition capacitance for a silicon diode when V D = 0? (Choose the best answer.) A. 1 pF B. 3 pF C. 5 pF D. 10 pF 31. Which of the following ratings is true?

INDIABIX ELECTRONICS

A.

B.

C.

D.

Si diodes have higher PIV and narrower temperature ranges than Ge diodes. Si diodes have higher PIV and wider temperature ranges than Ge diodes. Si diodes have lower PIV and narrower temperature ranges than Ge diodes. Si diodes have lower PIV and wider temperature ranges than Ge diodes.

32. The ideal diode is a(n) ________ circuit in the region of nonconduction. A. open B. short 33. Which capacitance dominates in the forward-bias region? A. Diffusion B. Transition C. Depletion D. None of the above 34. In what state is a silicon diode if the voltage drop across it is about 0.7 V? A. No bias B. Forward bias C. Reverse bias D. Zener region

DIODE APPLICATIONS 1. Determine the total discharge time for the capacitor in a clamper having C = 0.01µ F and R = 500 kΩ. A. 5 ms B. 25 ms C. 2.5 ms D. 50 ms

A. B. C. D.

clipper or limiter clamper IC voltage regulator none of the above

4. Each diode in a center-tapped fullwave rectifier is ________ -biased and conducts for ________ of the input cycle. A. forward, 90º B. reverse, 180º C. forward, 180º D. reverse, 90º 5. What is the voltage measured from the negative terminal of C 4 to the negative terminal of the transformer?

A. B. C. D.

–10 V –20 V 10 V 20 V

6. The output frequency of a full-wave rectifier is ________ the input frequency. A. one-half B. equal to C. twice D. one-quarter 7. PIV is which of the following? A. peak input voltage B. peak inverse voltage C. peak immediate voltage D. positive input voltage 8. Determine the peak value of the current through the load resistor.

VZ IZM IZ None of the above

3. What type of diode circuit is used to clip off portions of signal voltages above or below certain levels?

25 V 15 V –25 V –15 V

10. In a regulated supply, what term describes how much change occurs in the output voltage for a given change in the input voltage? A. load regulation B. voltage regulator C. line regulation D. ripple voltage 11. A short circuit has a ________ drop across its terminals, and the current is limited only by the surrounding network. A. 5V B. 0V C. 1V D. ∞ 12. Determine the peak for both half cycles of the output waveform.

A. B. C. D.

16 V, –4 V 16 V, 4 V –16 V, 4 V –16 V, –4 V

13. What is the peak inverse voltage across each diode in a voltage doubler? A. Vm B. 2Vm C. 0.5Vm D. 0.25V m

2. Which element dictates the maximum level of source voltage?

A. B. C. D.

A. B. C. D.

A. B. C. D.

2.325 mA 5 mA 1.25 mA 0 mA

9. Determine the peak value of the output waveform.

14. What is the VRRM (PIV rating) for the 1N4001 rectifier diode? A. 50 V B. 100 V C. 200 V D. 400 V E. none of the above 15. What type of diode circuit is used to add or restore a dc level to an electrical signal? A. clipper or limiter

INDIABIX ELECTRONICS

B. C. D.

clamper IC voltage regulator none of the above

20. What best describes the circuit?

16. Determine I D2.

A. B. C. D.

6.061 mA 0.7 mA 3.393 mA 3.571 mA

17. What is the logic function of this circuit?

A. B. C. D.

Full-wave rectifier Half-wave rectifier Clipper Clamper

21. What is the PIV for each diode in a full-wave center-tapped rectifier? Note: Vp(out) = peak output voltage. A. Vp(out) – 0.7 V B. Vp(out) + 0.7 V C. 2Vp(out) – 0.7 V D. 2Vp(out) + 0.7 V 22. Determine I D2.

25. If the ac supply is 50 Hz, what will be the ripple frequency out of the full-wave rectifier? A. 50 Hz B. 60 Hz C. 100 Hz D. 120 Hz 26. How many terminals do the 7800 series fixed positive voltage regulators have? A. 2 B. 3 C. 4 D. 5 E. none of the above 27. An open circuit can have any voltage across its terminals, but the current is always ________. A. B. C. D.

5A 0A 1A ∞

28. Determine I D1.

A. B. C. D.

Positive logic AND gate Positive logic OR gate Negative logic AND gate Negative logic OR gate

18. In a regulated supply, what term describes how much change occurs in the output voltage over a certain range of load current values, from minimum to maximum current? A. line regulation B. voltage regulator C. current regulator D. load regulation 19. Determine the average value of the current through the load resistor.

A. B. C. D.

2.5 mA 0 mA 1.37 mA 1.479 mA

A. B. C. D.

29.40 mA 30.30 mA 14.70 mA None of the above

23. Determine the current level if E = 15 V and R = 3 kΩ.

A. B. C. D.

0 mA 29.40 mA 14.70 mA 14.09 mA

29. Refer to the figure given below. Which diode arrangement will supply a negative output voltage? A. B. C. D.

0A 4.76 mA 5 mA 5A

24. Determine V2.

A. B. C. D.

3.201 V 0V 4.3 V 1.371 V

A. B. C. D.

a b c d

30. A silicon diode in a half-wave rectifier has a barrier potential of 0.7 V. This has the effect of

INDIABIX ELECTRONICS

A. B. C. D.

reducing the peak output voltage by 0.7 V. increasing the peak output voltage by 0.7 V. reducing the peak input voltage by 0.7 V. no effect.

31. What best describes the circuit?

A. B. C. D.

Full-wave rectifier Half-wave rectifier Clipper Clamper

32. Determine the value of the load resistor.

A. B. C. D.

RL = 5 kΩ RL = 5.5 kΩ RL = 6 kΩ None of the above

33. Use the information provided here to determine the value of I DQ.

A. B. C. D. A. B. C. D.

2 mA, 0 mA 4 mA, 2 mA 2 mA, 2 mA 2 mA, 4 mA

36. In the operation of a half-wave rectifier with a capacitor-input filter, the ripple factor can be lowered by ________ the value of the filter capacitor or ________ the load resistors. A. decreasing, decreasing B. decreasing, increasing C. increasing, decreasing D. increasing, increasing 37. Refer to the figure given below. The probable trouble, if any, indicated by these voltages is

A. B. C. D. E.

one of the diodes is open. a diode is shorted. an open transformer secondary. the filter capacitor is shorted. no trouble exists.

38. In a particular problem, which mode has the highest level of I DQ? A. Ideal B. Approximate equivalent C. Exact mode using characteristic curve D. None of the above

A. B. C. D.

0 mA 4.3 mA 5 mA 10 mA

34. If the ac supply is 60 Hz, what will be the ripple frequency out of the half-wave rectifier? A. 30 Hz B. 50 Hz C. 60 Hz D. 120 Hz 35. Calculate IL and IZ.

39. Which diode(s) has (have) a zero level current and voltage drop in the ideal model? A. Si B. Ge C. Both Si and Ge D. Neither Si nor Ge 40. Determine V o if E1 = E2 = 10 V.

9.3 V 10 V –10 V 0V

41. The output frequency of a half-wave rectifier is ________ the input frequency. A. one-half B. twice C. equal to D. none of the above 42. A diode is in the "________" state if the current established by the applied sources is such that its direction matches that of the arrow in the diode symbol, and VD ≥ 0.7 V for Si and VD ≥ 0.3 V for Ge. A. off B. on C. neutral D. quiescent 43. Determine I D.

A. B. C. D.

0 mA 1.893 mA 2.036 mA 2.143 mA

44. What best describes the circuit?

A. B. C. D.

Full-wave rectifier Half-wave rectifier Clipper Clamper

45. In a voltage-multiplier circuit, the number of diodes is directly proportional to the multiplicative voltage factor. A. True B. False 46. Rectifiers are commonly used in battery chargers. A. True B. False 47. List the categories of clippers. A. Series B. Parallel C. Series and parallel D. None of the above

INDIABIX ELECTRONICS

48. A silicon diode has a voltage to ground of –117 V from the anode. The voltage to ground from the cathode is – 117.7 V. The diode is A. open. B. shorted. C. forward-biased. D. reverse-biased.

52. Refer to the figure given below. If the voltmeter across the transformer reads 0 V, the probable trouble, if any, would be

49. Which diode arrangement will supply a positive output voltage?

A. B. C. D. E.

one of the diodes is open. a diode is shorted. an open transformer secondary. the filter capacitor is shorted. no trouble exists.

C. D.

the transistor being driven into cutoff. all of the above

2. Which transistor bias circuit arrangement provides good stability using negative feedback from collector to base? A. base bias B. collector-feedback bias C. voltage-divider bias D. emitter bias 3. Refer to the given figure. The most probable cause of trouble, if any, from these voltage measurements is

53. Determine the voltage across the resistor.

A. B. C. D.

a b c d

50. What is the logic function of this circuit?

A. B. C. D.

0V 0.09 V 0.2 V 0.44 V

54. With this Zener diode in its "on state," what is the level of I Z for the maximum load resistance?

A. B. C. D.

A. B. C. D.

Positive logic AND gate Positive logic OR gate Negative logic AND gate Negative logic OR gate

51. Determine the current through each diode if E 1 = E2 = 0 V.

A. B. C. D.

0 mA Undefined Equal to IRL IZM

4. Refer to the given figure. The most probable cause of trouble, if any, from these voltage measurements is

55. In a voltage regulator network with fixed RL and R, what element dictates the minimum level of source voltage? A. VZ B. IZ C. IZM D. None of the above A.

TRANSISTOR BIAS CIRCUITS A. B. C. D.

4.65 mA 9.3 mA 18.6 mA 0.7 mA

the base-emitter junction is open. RE is open. a short from collector to emitter. no problems.

1. Clipping is the result of A. the input signal being too large. B. the transistor being driven into saturation.

B. C. D.

the base-emitter junction is open. RE is open. a short from collector to emitter. no problems.

5. What is the dc input resistance at the base of a BJT? A. βDCRC B. βDC · (RC || RE )

INDIABIX ELECTRONICS

C. D.

βDC·re′ βDCRE

6. Which transistor bias circuit provides good Q-point stability with a singlepolarity supply voltage? A. base bias B. collector-feedback bias C. voltage-divider bias D. emitter bias 7. Refer to this figure. In the voltagedivider biased npn transistor circuit, if R 2 opens, the transistor is

11. What is the Q-point for a fixed-bias transistor with I B = 75µ A, β DC = 100, VCC = 20 V, and RC = 1.5 kΩ? A. VC = 0 V B. VC = 20 V C. VC = 8.75 V D. VC = 11.25 V 12. Emitter bias requires A. only a positive supply voltage. B. only a negative supply voltage. C. no supply voltage. D. both positive and negative supply voltages. 13. Refer to this figure. The value of β DC is

A. B. C.

saturated. cutoff. nonconducting.

16. Which transistor bias circuit arrangement has poor stability because its Q-point varies widely with βDC? A. base bias B. collector-feedback bias C. voltage-divider bias D. emitter bias 17. What is the most common bias circuit? A. base B. collector C. emitter D. voltage-divider 18. Refer to the given figure. The most probable cause of trouble, if any, from these voltage measurements would be

A. B. C.

saturated. cutoff. nonconducting.

8. Ideally, for linear operation, a transistor should be biased so that the Q-point is A. near saturation. B. near cutoff. C. where IC is maximum. D. halfway between cutoff and saturation.

A. B. C. D.

5.3. 53. 94. 100.12.

14. Refer to this figure. Assume that IC≈IE. Find VE.

A.

9. The most stable biasing technique used is the A. voltage-divider bias. B. base bias. C. emitter bias. D. collector bias. 10. Refer to this figure. The value of I B is

B. C. D.

the base-emitter junction is open. RE is open. a short from collector to emitter. no problems.

19. Refer to this figure. Determine I C. A. B. C. D.

5V 10 V 15 V 2.5 V

15. Refer to this figure. In the voltagedivider biased npn transistor circuit, if R C opens, the transistor is

A. B. C. D.

53 µA. 50 µA. 50 mA. 53 mA.

A. B. C. D.

5A 5 mA 0 mA 10 mA

20. At saturation the value of V CE is nearly ________, and IC = ________. A. zero, zero

INDIABIX ELECTRONICS

B. C. D.

VCC, IC(sat) zero, I(sat) VCC, zero

B. C.

29. Changes in βDC result in changes in A. IC. B. VCE. C. the Q-point. D. all of the above

21. Voltage-divider bias has a relatively stable Q-point, as does A. base bias. B. collector-feedback bias. C. both of the above D. none of the above 22. Refer to this figure. Assume I C≈IE. Determine the value of R C that will allow VCE to equal 10 V.

cutoff. nonconducting.

A. B. C. D.

10 µA. 10 mA. 5 mA. 50 mA.

DC BIASING BJTs 1. Calculate VCE.

26. Which transistor bias circuit arrangement provides good Q-point stability, but requires both positive and negative supply voltages? A. base bias B. collector-feedback bias C. voltage-divider bias D. emitter bias A. B. C. D.

1 kΩ 1.5 kΩ 2 kΩ 2.5 kΩ

27. Refer to this figure. Calculate the current I2.

23. The linear (active) operating region of a transistor lies along the load line below ________ and above ________. A. cutoff, saturation B. saturation, cutoff 24. The input resistance of the base of a voltage-divider biased transistor can be neglected A. at all times. B. only if the base current is much smaller than the current through R2 (the lower bias resistor). C. at no time. D. only if the base current is much larger than the current through R2 (the lower bias resistor).

A. B. C. D.

32 mA 3.2 mA 168 µA 320 µA

28. Refer to this figure. In the voltagedivider biased npn transistor circuit, if R 1 opens, the transistor is

25. Refer to this figure. The value of I C is

A.

saturated.

A. B. C. D.

–4.52 V 4.52 V –9 V 9V

2. For the BJT to operate in the active (linear) region, the base-emitter junction must be ________-biased and the basecollector junction must be ________biased. A. forward, forward B. forward, reverse C. reverse, reverse D. reverse, forward 3. The cutoff region is defined by IB ________ 0 A. A. > B. < C. ≤ D. ≥ 4. Determine the reading on the meter when VCC = 20 V, R C = 5 kΩ, and IC = 2 mA.

INDIABIX ELECTRONICS

A. B. C. D.

10 V –10 V 0.7 V 20 V

5. In a fixed-bias circuit, which one of the stability factors overrides the other factors? A. S(ICO) B. S(VBE) C. S(β) D. Undefined 6. Calculate the voltage across the 91 kΩ resistor.

A. B. C. D.

18 V 9.22 V 3.23 V None of the above

7. Calculate the value of VCEQ.

A. B. C. D.

20 50 75 116

10. Determine the change in I C from 25ºC to 175ºC for the transistor defined in this table for fixed-bias with R B = 240 kΩ and β= 100 due to the S(VBE) stability factor.

A. B. C. D.

145.8 µA 145.8 nA –145.8 µ A –145.8 nA

11. Which of the following is (are) related to an emitter-follower configuration? A. The input and output signals are in phase. B. The voltage gain is slightly less than 1. C. Output is drawn from the emitter terminal. D. All of the above A. B. C. D.

8.78 V 0V 7.86 V 18 V

8. Calculate the approximate value of the maximum power rating for the transistor represented by the output characteristics of Figure 4.1? A. 250 mW B. 170 mW C. 50 mW D. 0 mW 9. For what value of β does the transistor enter the saturation region?

12. At what region of operation is the base-emitter junction forward biased and the base-collector junction reverse biased? A. Saturation B. Linear or active C. Cutoff D. None of the above 13. You can select the values for the emitter and collector resistors from the information that is provided for this circuit.

A. B.

True False

14. In the case of this circuit, you must assume that VE = 0.1·VCC in order to calculate RC and RE.

A. B.

True False

15. For an "on" transistor, the voltage V BE should be in the neighborhood of 0.7 V. A. True B. False 16. In a voltage-divider circuit, which one of the stability factors has the least effect on the device at very high temperature? A. S(ICO) B. S(VBE) C. S(β) D. Undefined 17. Which of the following is (are) a stability factor? A. S(ICO) B. S(VBE) C. S(β) D. All of the above 18. Calculate ICsat.

INDIABIX ELECTRONICS

23. Which of the following voltages must have a negative level (value) in any npn bias circuit? A. VBE B. VCE C. VBC D. None of the above

A. B.

True False

29. Calculate Rsat if VCE = 0.3 V.

24. Determine the values of V CB and IB for this circuit.

A. B. C. D.

35.29 mA 5.45 mA 1.86 mA 4.72 mA

19. Calculate the storage time in a transistor switching network if t off is 56 ns, tf = 14 ns, and t r = 20 ns. A. 70 ns B. 42 ns C. 36 ns D. 34 ns 20. Determine I CQ at a temperature of 175º C if I CQ = 2 mA at 25º C for R B / RE = 20 due to the S(β) stability factor. A. 2.417 mA B. 2.392 mA C. 2.25 mA D. 2.58 mA 21. Calculate ETh for this network.

A. B. C. D. A. B. C. D.

1.4 V, 59.7 µA –1.4 V, 59.7 µA –9.3 V, 3.58 µA 9.3 V, 3.58 µA

25. Use this table to determine the change in IC from 25ºC to 175ºC for R B / RE = 250 due to the S(I CO) stability factor. Assume an emitter-bias configuration.

A. B. C. D.

140.34 nA 140.34 µA 42.53 nA 0.14034 nA

26. For the typical transistor amplifier in the active region, VCE is usually about ________ % to ________ % of V CC. A. 10, 60 B. 25, 75 C. 40, 90

A. B. C. D.

−12.12 V 16.35 V −3.65 V 10 V

22. Which of the following currents is nearly equal to each other? A. IB and IC B. IE and IC C. IB and IE D. IB, IC, and IE

27. For the BJT to operate in the saturation region, the base-emitter junction must be ________-biased and the base-collector junction must be ________-biased. A. forward, forward B. forward, reverse C. reverse, reverse D. reverse, forward 28. The total time required for the transistor to switch from the "off" to the "on" state is designated as t on and defined as the delay time plus the time element.

49.2 Ω 49.2 k Ω 49.2 m Ω 49.2 M Ω

30. The ratio of which two currents is represented by β? A. IC and IE B. IC and IB C. IE and IB D. None of the above 31. Which of the following is assumed in the approximate analysis of a voltage divider circuit? A. IB is essentially zero amperes. B. R1 and R2 are considered to be series elements. C. RE ≥ 10R2 D. All of the above 32. The saturation region is defined by VCE ________ VCEsat. A. > B. < C. ≤ D. ≥ 33. Calculate VCE.

A. B. C. D.

4.52 V –4.52 V 4.48 V –4.48 V

34. Which of the following is (are) the application(s) of a transistor? A. Amplification of signal B. Switching and control

INDIABIX ELECTRONICS

C. D.

Computer logic circuitry All of the above

35. It is desirable to design a bias circuit that is independent of the transistor beta. A. True B. False

FIELD EFFECT TRANSISTORS

B. C. D.

8V 6V 2V

5. A self-biased n-channel JFET has a V D = 6 V. V GS = –3 V. Find the value of V DS. A. –3 V B. –6 V C. 3V D. 6V 6. Refer to the given figure. I D = 6 mA. Calculate the value of VDS.

A. B. C. D.

–9 V 9V 6V –3 V

3. Refer to figure given below. Calculate the value of VDS. 7. What type(s) of gate-to-source voltage(s) can a depletion MOSFET (DMOSFET) operate with? A. zero B. positive C. negative D. any of the above

A. B. C. D.

8. Midpoint bias for a D-MOSFET is I D = ________, obtained by setting V GS = 0. A. IDSS / 2 B. IDSS / 3.4 C. IDSS

0V 2V 4V –2 V

4. Refer to figure shown Determine the value of V S.

below.

–6 V 6V 12 V –3 V

11. Refer to figure given Determine the value of V GS.

1. For a JFET, the value of V DS at which ID becomes essentially constant is the A. pinch-off voltage. B. cutoff voltage. C. breakdown voltage. D. ohmic voltage. 2. The ________ has a physical channel between the drain and source. A. D-MOSFET B. E-MOSFET C. V-MOSFET

A. B. C. D.

9. On the drain characteristic curve of a JFET for VGS = 0, the pinch-off voltage is A. below the ohmic area. B. between the ohmic area and the constant current area. C. between the constant current area and the breakdown region. D. above the breakdown region.

A. B. C. D.

–20 V –8 V –6 V –2 V

12. Which of the following devices has the highest input resistance? A. diode B. JFET C. MOSFET D. bipolar junction transistor 13. The value of VGS that makes ID approximately zero is the A. pinch-off voltage. B. cutoff voltage. C. breakdown voltage. D. ohmic voltage. 14. The JFET is always operated with the gate-source pn junction ________ biased. A. forward B. reverse 15. Identify the p-channel D-MOSFET.

10. Refer to the given figure. I D = 6 mA. Calculate the value of VDS. A. B. C. D. A.

20 V

below.

a b c d

INDIABIX ELECTRONICS

16. All MOSFETs are subject to damage from electrostatic discharge (ESD). A. true B. false 17. Identify the n-channel D-MOSFET.

A. B. C. D.

24. For a JFET, the change in drain current for a given change in gate-tosource voltage, with the drain-to-source voltage constant, is A. breakdown. B. reverse transconductance. C. forward transconductance. D. self-biasing.

a b c d

18. A dual-gated MOSFET is A. a depletion MOSFET. B. an enhancement MOSFET. C. a VMOSFET. D. either a depletion or enhancement MOSFET.

23. High input resistance for a JFET is due to A. a metal oxide layer. B. a large input resistor to the device. C. an intrinsic layer. D. the gate-source junction being reverse-biased.

25. Identify the p-channel E-MOSFET.

A. B. C. D.

20 V 8V 6V 2V

20. What three areas are the drain characteristics of a JFET (V GS = 0) divided into? A. ohmic, constant-current, breakdown B. pinch-off, constant-current, avalanche C. ohmic, constant-voltage, breakdown 21. In a self-biased JFET circuit, if V D = VDD then ID = ________. A. 0 B. cannot be determined from information above 22. The resistance of a JFET biased in the ohmic region is controlled by A. VD. B. VGS. C. VS . D. VDS.

a b c d

30. If VD is less than expected (normal) for a self-biased JFET circuit, then it could be caused by a(n) A. open RG. B. open gate lead. C. FET internally open at gate. D. all of the above

a b c d

26. Refer to figure shown below. What is the value of IG?

A. B. C. D.

A. B. C. D.

31. Refer to the given figure. I D = 6 mA. Calculate the value of VDS.

an

19. Refer to figure show below. Calculate the value of VD.

29. Identify the n-channel E-MOSFET.

A. B. C. D.

13.2 V 10 V 6.8 V 0V

DC BIASING FETs 1. Calculate the value of VDS. A. B. C. D.

6 mA 4 mA 2 mA 0 mA

27. A JFET data sheet specifies V GS(off) = – 6 V and I DSS = 8 mA. Find the value of I D when VGS = –3 V. A. 2 mA B. 4 mA C. 8 mA D. none of the above 28. A JFET data sheet specifies V GS(off) = – 10 V and IDSS = 8 mA. Find the value of I D when VGS = –3 V. A. 2 mA B. 1.4 mA C. 4.8 mA D. 3.92 mA

A. B. C. D.

0V 0.35 V 3.8 V 33.5 V

2. Calculate the value of V DS.

INDIABIX ELECTRONICS

A. B. C. D.

0V 8V 4.75 V 16 V

3. Given the values of V DQ and IDQ for this circuit, determine the required values of RD and RS.

11. On the universal JFET bias curve, the vertical scale labeled ________ can, in itself, be used to find the solution to ________ configurations. A. m, fixed-bias B. M, fixed-bias C. M, voltage-bias D. m, voltage-bias 12. Calculate the value of R S. Assume VGSQ = −2V. A. B. C. D.

10 MΩ 100 MΩ 110 MΩ 220 MΩ

7. Which of the following is (are) true of a self-bias configuration compared to a fixed-bias configuration? A. One of the dc supplies is eliminated. B. A resistor RS is added. C. VGS is a function of the output current ID. D. All of the above A. B. C. D.

2 kΩ, 2 kΩ 1 kΩ, 5.3 kΩ 3.2 kΩ, 400 Ω 2.5 kΩ, 5.3 kΩ

4. For what value of R D is the voltage across VDS zero?

A. B. C. D.

2.400 kΩ 5.167 kΩ 6.167 kΩ 6.670 kΩ

A. B. C. D.

0 kΩ 1.68 kΩ 6.81 kΩ 8.5 kΩ

13. Calculate the value of R D.

8. The input controlling variable for a(n) ________ is a current level and a voltage level for a(n) ________. A. BJT, FET B. FET, BJT C. FET, FET D. BJT, BJT 9. Through proper design, a ________ can be introduced that will affect the biasing level of a voltage-controlled JFET resistor. A. photodiode B. thermistor C. laser diode D. Zener diode

A. B. C. D.

2 kΩ 3 kΩ 3.5 kΩ 4.13 kΩ

14. At what value of R S does the circuit switch from depletion mode to enhancement mode?

10. For what value of R S can the depletion-type MOSFETs operate in enhancement mode?

5. For the FET, the relationship between the input and output quantities is ________ due to the ________ term in Shockley's equation. A. nonlinear, cubed B. linear, proportional C. nonlinear, squared 6. For what value of R 2 is VGSQ equal to 1 V?

A. B. C. D.

2.4 kΩ 5 kΩ 6.2 kΩ None of the above

A. B. C. D.

250 Ω 500 Ω 10 M Ω None of the above

INDIABIX ELECTRONICS

15. Which of the following current equations is true? A. IG = ID B. IG = IS C. ID = IS D. IG = ID = IS

D.

Both are obtained by writing Kirchhoff's voltage law (KVL) at the input side loop

21. Calculate VDS.

16. Calculate VDSQ. A. B. C. D.

A. B. C. D.

1.0 V 1.50 V 2.56 V 3.58 V

17. Calculate the value of V DS.

A. B. C. D.

0V 6V 16 V 11 V

0V 20 V 30 V 40 V

26. What is the approximate current level in the gate of an FET in dc analysis? A. 0A B. 0.7 mA C. 0.3 mA D. Undefined 27. Calculate V D.

22. For the noninverting amplifier, one of the most important advantages associated with using a JFET for control is the fact that it is ________ rather than ________ control. A. dc, ac B. ac, dc 23. What are the voltages across R D and RS?

A. B. C. D.

A. 23.0 V B. 17.0 V C. 4.6 V D. 12.4 V 28. Calculate VCE.

–3 V 3V –4 V 4V

18. Which of the following represents the voltage level of VGS in a self-bias configuration? A. VG B. VGS(off) C. VS D. VP 19. The self-bias configuration eliminates the need for two dc supplies. A. True B. False 20. Which of the following is a false statement regarding the dc load line when comparing self-bias and voltagedivider configurations? A. Both are linear lines. B. Both cross the origin. C. Both intersect the transfer characteristics.

A. B. C. D.

0 V, 0 V 5 V, 5 V 10 V, 10 V 20 V, 20 V

24. Depletion-type MOSFETs do not permit operating points with positive values of VGS and levels of I D that exceed IDSS. A. True B. False 25. Calculate the value of VDSQ.

A. B. C. D.

0V 2V 3V 5.34 V

29. Seldom are current levels measured since such maneuvers require disturbing the network structure to insert the meter. A. True B. False

INDIABIX-Part 1-ELEX-MCQs.pdf

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