Multiple Choice Questions from Electrostatics and Current Electricity

MULTIPLE CHOICE QUESTIONS-I 1.

There is a repulsive force between two charged objects when a. charges are of unlike sign b. they have the same number of protons c. charges are of like sign d. they have the same number of electrons

2.

When there is an equal amount of positive and negative charges on an object, the object is ___________________ . a. positively charged b. negatively charged c. neutral. d. supercharged

3.

Every charged particle produces __________________ . a. a negative charge b. a positive charge c. a magnetic field. d. an electric field

4.

What is the electrical potential difference between two places measured in? a. amperes b. volts c. coulombs d. joules

5.

6.

7.

8.

9.

Current is the rate at which charges move through a(n) a. conductor b. insulator c. voltage d. amperes

12. The magnetic field lines inside a long, current carrying solenoid are nearly a. straight b. circular c. parabolic d. elliptical 13. Who first discovered the relationship between electricity and magnetism? a. Faraday b. Newton c. Maxwell d. Oersted 14. The direction of the force on a current-carrying wire placed in a magnetic field depends on a. the direction of the current b. the direction of the field c. the direction of current as well as field d. neither the direction of current nor the direction of field 15. For making a strong electromagnet, the material of the core should be a. soft iron b. steel c. brass d. copper 16. A fuse in an electric circuit acts as a a. current multiplication b. voltage multiplication c. power multiplier d. safety device

Electrical potential differences cause a. electrons to move from the positive terminal to the negative terminal 17. Kilowatt-hour is the unit of b. electrons to move from the negative terminal to the positive a. potential difference b. electric power terminal c. electrical energy d. charge c. protons to move from the positive terminal to the negative terminal 18. When a fuse is rated 8A, it means d. protons to move from the negative terminal to the positive a. it will not work if current is less than 8A terminal b. it has a resistance of 8 c. it will work only if current is 8A Appliances connected so that they form a single pathway for d. it will burn if current exceeds 8A charges to flow are connected in a(n) ____________ . a. series circuit b. open circuit 19. Can a body have charge and still be at zero potential? c. parallel circuit d. closed circuit a. Yes, always b. Yes, but not always The north pole of one magnet will be ________________ . c. Never a. attracted to the north pole of another magnet. d. Depends upon the nature of the charge b. attracted to the south pole of the another magnet  c. stick to the north pole of another magnet 20. Torque acting on electric dipole of dipole moment p placed  d. repelled by the south pole of another magnet in a uniform electric field E is       Where is the magnetic force strongest in a magnet? a. p  E b. p  E c. zero d. E  p a. near the center of the magnet b. at the poles of the magnet 21. In S.I unit of electric field is c. in the middle of the magnetic field 1 1 1 2 d. The magnetic force is the same everywhere. a. Am b. NC c. Cm d. Cm

10. Where does a compass needle naturally points toward? a. the geographic North Pole b. the S pole of a magnet c. the geographic South Pole d. Earth's North Magnetic Pole 11. The magnetic field lines due to a straight wire carrying a current are a. straight b. circular c. parabolic d. elliptical

22. Static electricity is produced due to a. friction b. conduction c. induction d. both A and C 23. In the direction of electric field, the electric potential a. decreases b. increases c. becomes zero d. remains unchanged 24. Potential at any point inside a charged hollow sphere a. increases with distance b. is a constant c. is zero d. decreases with distance from centre.

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25. When air is replaced by a dielectric medium of constant K the maximum capacitance of the capacitor a. decreases K times b. increases K times c. increases K2 times d. remains unchanged

35. The temperature of a hot junction, at which the thermo e.m.f is maximum, is a. neutral temperature b. temperature of inversion c. transition temperature d. critical temperature

26. What is the equivalent capacitance of the following circuit?

36. The plot showing the variation of thermo e.m.f with temperature of hot junction of a thermocouple is a. circular b. elliptical c. parabolic d. hyperbolic 37. Identify the material commonly used for making the coils of resistance box: a. Molybdenum b. Manganese c. Manganin d. magnesium

a. 1F c. 3F

b. 2F d. 1.5F

27. The energy stored in a capacitor of capacitance C and potential V is given by a.

1 2 C V 2

b.

1 CV 2 2

c. 1 CV 2

d.

1 2 2 C V 2

28. A current of 2A passing through a conductor produces 80J of heat in 10 secs. The resistance of the conductor is a. 0.5 b. 2 c. 4 d. 20 29. Two bulbs 25W-220V and 100W and 220V are given. Which has higher resistance? a. 25W bulb b. 100W bulb c. Both bulbs have equal resistances d. Resistances of the bulb cannot be compared 30. Watt-hour meter measures a. electrical energy c. voltage

b. current d. power

38. Si and Cu are cooled to a temperature of 300K. then resistivity a. for Si increases and for Cu decreases b. for Cu increases and for Si decreases c. decreases for both Si and Cu d. increases for both Si and Cu 39. Two copper wires, one of length 1m and the other of length 9m, are found to have the same resistance. Their diameters are in the ratio a. 3:1 b. 1:9 c. 9:1 d. 1:3 40. A conductor of resistance 8 is bent in the form of a circle. What will be the resistance between two points on any diameter of the circle? a. 1 b. 2 c. 8 d. 16 41. Kirchoff’s first law deals with the conservation of a. energy b. heat c. charge d. momentum 42. Figure shows current in a part of electrical circuit. Then, current I is

31. If the current flowing in a conductor changes by 1%, then power will change by a. 1% b. 2% c.10% d. 100% 32. The heating element of a heater should be made with a material which should have a. high resistivity and high melting point b. high resistivity and low melting point c. low resistivity and low melting point d. low resistivity and high melting point 33. Of the two bulbs in a house, one glows brighter than the other. Which of the two has a larger resistance? a. the brighter bulb b. the dim bulb c. both have same resistance d. the brightness does not depend upon resistance 34. When current flows through a conductor, heat is produced. This is a. Seebeck effect b. Thomson effect c. Petlier effect d. Joule effect

a. 1.7A c.1.3A

b. 3.7A d. 1A

43. To convert a galvanometer into an ammeter, we connect a. Low resistance in series b. Low resistance in parallel c. High resistance in series d. High resistance in parallel 44. Tesla is the unit of magnetic a. Field c. induction

b. flux d. moment

45. The magnetic field at a distance r from a long wire carrying current I is 0.4 Tesla. The magnetic field at a distance 2r is a. 0.1 T b. 0.8T c. 0.2T d. 1.6T

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