Physics Objective Question

Q. A light year is a unit of 1

Velocity

2

Distance

3

Time

4

Energy Ans: 2

Q. Which one among the following is not a mixture? 1

Graphite

2

Steel

3

Glass

4

Brass Ans: 1

Q. Which one among the following most correctly determines the atomic number of an element? 1

Number of protons and electrons

2

Number of nucleons

3

Number of ions

4

Number of protons Ans: 4

Q. Which one among the following is used to make periscope? 1

Concave lens

2

Concave mirror

3

Plane mirror

4

None of these Ans: 3

Q. Kilowatt-hour is the unit of 1 electric energy 2 electric power 3 electric potential 4 potential difference Ans: 1 Q. A stable nucleus (light with A < 10) has 1 no protons 2 no neutrons 3 exactly the same number of neutrons and protons 4 more neutrons than protons Ans: 3 Q. Which one among the following waves are called waves of heat energy? 1

Radio waves

2

Microwaves

3

Ultraviolet waves

4

Infrared waves

Ans: 4 Q. Ultrasonic waves are those sound waves having frequency 1

between 20 hertz and 1000 hertz

2

between 1000 hertz and 20000 hertz

3

less than 20 hertz

4

more than 20 kilohertz Ans: 4

Q. The best colours for a Sun umbrella will be 1

white on top and black on inside

2

red on top and black on inside

3

black on top and white on inside

4

black on top and red on inside Ans: 1

Q. Before X-ray examination (coloured X-ray) of the stomach, patients are given suitable salt of barium because 1

barium is a good absorber of X-rays and helps stomach to appear clearly

2

barium salts are white in colour and this helps stomach to appear clearly

3

barium allows X-rays to pass through the stomach

4

barium salts are easily available Ans: 1

Q. In SONAR, we use 1 radio waves 2 audible sound waves 3 infrasonic waves 4 ultrasonic waves Ans: 4 Q. A liquid is kept in a regular cylindrical vessel up to a certain height. If this vessel is replaced by another cylindrical vessel having half the area of cross-section of the bottom, the pressure on the bottom will 1

be increased to twice the earlier pressure

2

be reduced to one-fourth the earlier pressure

3

remain unaffected

4

be reduced to half the earlier pressure Ans: 1

Q. The time period of a simple pendulum having a spherical wooden bob is 2 second. If the bob is replaced by a metallic one twice as heavy, the time period will be 1

more than 2 second

2

1 second

3

2 second

4

less than 1 second Ans: 3

Q. Which one among the following statements about an atom is not correct?

1 Atoms are the basic units from which molecules and ions are formed 2 Atoms always combine to form molecules 3 Atoms aggregate in large numbers to form the matter that we can see, feel and touch 4 Atoms are always neutral in nature Ans: 3 Q. The working principle of a washing machine is 1

Dialysis

2

Centrifugation

3

Reverse osmosis

4

Diffusion Ans: 2

Q. A spherical ball made of steel when dropped in mercury container will 1

sink in mercury

2

will be on the surface of mercury

3

will be partly immersed in mercury

4

will dissolve in mercury Ans: 3

Q. The sounds having a frequency of 20 Hertz to 20,000 Hertz are known as 1

Ultrasonics

2

Audible sounds

3

Infrasonics

4

Megasonics Ans: 2

Q. Pure water is bad conductor of electricity because it is 1

not volatile

2

feebly ionized

3

a non-polar solvent

4

a very good solvent Ans: 2

Q. The metals commonly used for electroplating are 1

Gold, Sodium & Chromium

2

Chromium, Copper & Nickel

3

Nickel, Lead & Chromium

4

Gold, Sodium & Potassium Ans: 2

Q. Gamma rays have greatest similarity with 1

a-rays

2

b-rays

3

X-rays

4

U.V.rays Ans: 3

Q. Two 220 V, 60 W bulbs are used for 5 hours a day for 10 days. If each unit (1 kilowatt hour) costs Rs. 3.50, find the total expense for it 1

Rs. 10.50

2

Rs. 38.50

3

Rs. 77.00

4

Rs. 21.00 Ans: 4

Q. There are four statements gives below explaining why mercury is chosen as a thermometric liquid. which of these statements is wrong? 1

Volume of mercury increases equally for equal rises of temperature

2

Mercury is a good conductor of heat

3

Mercury does not stick to glass

4

Mercury has a large specific heat Ans: 1

Q. The internal energy of a body means 1 Sum total of its kinetic and potential energy of its constituent molecules. 2 its kinetic energy 3 Total kinetic energy of its constituent moleules 4 Sum total of its kinetic and potential energy Ans: 1 Q. Which of the following is a dimensionless quantity? 1

Acceleration

2

Volume

3

Refractive Index

4

Kinetic energy Ans: 3

Q. Four wires of same material and different dimensions are stretched under the equal weight, which one will suffer greater elongation? The dimensions are given below 1

Length 100 cm, diameter 1 mm

2

Length 200 cm, diameter 2 mm

3

Length 300 cm, diameter 3 mm

4

Length 400 cm, diameter 0.5 mm Ans: 4

Q. Water is used in hot water bags because 1 it is easily obtained 2 it has high specific heat 3 it is cheaper and is not harmful 4 it is easy to heat water Ans: 2 Q. Water drops cannot stick to the oily surface due to 1

surface tension

2

lack of adhesive force

3

water is lighter than oil

4

cannot mix each other Ans: 2

Q. Energy in reflected light 1 does not depends on the angle of incidence 2 decreases with the increase in angle of incidence 3 increases with the increase in angle of incidence 4 becomes maximum for angle of incidence equal to 45 degree Ans: 1 Q. The unit of power is called 1

Watt

2

Dyne

3

Erg

4

Ohm Ans: 1

Q. The sound produced by a bat is 1

Ultrasonic

2

Infrasonic

3

Audible

4

Subsonic Ans: 1

Q. When a bar magnet is cut into two equal halves, the pole strength of each piece 1

Becomes zero

2

Remains the same

3

Becomes Half

4

Becomes Double Ans: 2

Q. In a refrigerator, cooling is produced by 1 the evaporation of a volatile liquid 2 the sudden expansion of a compressed gas 3 the ice which deposits on the freezer 4 None of the above Ans: 1 Q. Which principle states that when a body is partially or totally immersed in a fluid, it experiences an upward thrust equal to the weight of fluid displaced by it: 1

Archimedes'

2

Hooke's

3

Pascal's

4

Newton's Ans: 1

Q. Cream gets separated from milk when it is churned because of:

1

Gravitational force

2

Centrifugal force

3

Frictional force

4

Cohesive force Ans: 2

Q. Speed of sound is maximum in: 1

Gas

2

Same in all cases

3

Liquid

4

Solid Ans: 4

Q. Newton is a unit of: 1

Force

2

Acceleration

3

Work

4

Energy Ans: 1

Q. The mass of a body at the centre of earth is: 1

Zero

2

Remains constant

3

More than at the surface

4

Less than at the surface Ans: 2

Q. 1 Joule is equivalent to 1

103ergs

2

105 ergs

3

107ergs

4

1011 Ans: 3

Q. The coating of a thin layer of zinc on steel or iron objects is known as 1

Galvanising

2

Hot dipping

3

Tinning

4

Electroplating Ans: 1

Q. Electric current in a metal wire is due to the flow of 1

Protons

2

Electrons

3

Ions

4

None of these Ans: 2

Q. Optic fibres are mainly used for 1

Weaving

2

Communication

3

Musical instruments

4

Food industry Ans: 2

Q. Which among the following is a chemical change? 1 A wet towel dries in the sun 2 Lemon juice added to tea causing its colour to change 3 Coffee is brewed by passing steam through ground coffee 4 Hot air rises over a radiator Ans: 2 Q. Which of the following is a vector quantity? 1

Force

2

Temperature

3

Energy

4

Momentum Ans: 1

Q. At what point the Centigrade and the Fahrenheit temperatures are the same? 1

10 degree

2

0 degree

3

-10 degree

4

-40 degree Ans: 4

Q. Which among the following is an element? 1

Alumina

2

Brass

3

Graphite

4

Silica Ans: 3

Q. In electro discharge machining, cutting tools are usually made of 1

High speed steel

2

Tool steel

3

Carbide-tipped tool

4

Graphite Ans: 4

Q. Glass is made of 1 Sand & Silicate 2 Quartz & Mica 3 Sand & Silt 4 None of these

Ans: 2 Q. Which of the following is called strategic metal? 1

Silicon

2

Titanium

3

Uranium

4

Germanium Ans: 3

Q. Heavy water is 1 Sea water(H2O + salt) 2 D2O2 3 H2O2 4 None of the above Ans: 2 Q. The operation of threading a drilled hole is called 1

Tapping

2

Broaching

3

Lapping

4

Reaming Ans: 1

Q. The first symbol in a grinding wheel code is the 1

Bond Type

2

Grain size

3

Structure

4

Abrasive Type Ans: 4

Q. Thermit welding is a form of 1

Gas welding

2

Fusion welding

3

Resistance welding

4

Arc welding Ans: 2

Q. Electrode gets consumed in which type of welding process? 1

Arc

2

Thermit

3

T.I.G.

4

Gas Ans: 1

Q. Which of the following metals can be easily drawn into the wire? 1

Lead

2

Copper

3

Tin

4

Zinc Ans: 2

Q. Base of a transistor is 1 Heavily doped 2 Moderately doped 3 Lightly doped 4 None of the above Ans: 4 Q. Lube oil is used in diesel engines 1

To ignite

2

To cool the engine

3

To reduce friction

4

2 and 3 both Ans: 4

Q. Air is charged in the cylinder of diesel engine by 1

Exhaust valve

2

Inlet valve

3

Injector

4

Air Box Ans: 2

Q. Type of filter fitted in a tractor is 1

Paper Type

2

Cotton Type

3

Oil-bath Type

4

Wire Mesh Type Ans: 1

Q. Nichrome is commonly used for 1

Transformer windings

2

Battery connetions

3

Lamp filament

4

Heater coils Ans: 4

Q. In a telescope of magnification power 10, the focal length of the objective lens is 60 cm, what will be the total length of eyepiece 1

6 cm

2

25 cm

3

30 cm

4

50 cm Ans: 1

Q. A hollow cylindrical rod is filled with air, to make it a resonance column. To produce a wave of length 48 cm the minimum length of rod should be

1

12 cm

2

24 cm

3

48 cm

4

96 cm Ans: 2

Q. An object is placed between the pole of concave mirror and the focus of the mirror, the image formed will be 1

Behind the mirror, virtual, erect and magnified

2

At infinity, real inverted and highly enlarged

3

Byond centre of curvature, real inverted and enlarged

4

Beyond 2F, real inverted and enlarged Ans: 1

Q. When 1 litre of water freezes, the volume of ice formed will be 1

0.9 litre

2

1.0 litre

3

1.11 litre

4

1.5 litre Ans: 3

Q. A body is thrown vertically upwards with a speed of 100 m/sec. While coming back on ground, its speed at starting point will be 1

100 m/sec

2

1000 m/sec

3

50 m/sec

4

200 m/sec Ans: 1

Q. Which one of the following is not a radioactive element? 1

Uranium

2

Radium

3

Thorium

4

Cadmium Ans: 4

Q. Superconductors are those materials 1 Which become non-conductors at transition point 2 Which looses all electrical resistance when cooled below a certain temperature 3 In which resistance rises to infinity below certain temperature 4 Which conducts electricity in extra widths Ans: 2 Q. Which of the following is a physical change? 1

Boiling of Water

2

Rusting of Iron

3

Boiling of an Egg

4

Burning of Candle

Ans: 1 Q. In an atom no two electrons have all the four quantum numbers identical. This is known as 1

Paulis Exclusion principle

2

Hunds Rule

3

Aufbau Principle

4

Avogadros Law Ans: 1

Q. What is the power factor of a pure resistor circuit? 1

One

2

Zero

3

Leading

4

Lagging Ans: 1

Q. A transformer mainly transforms 1

Current

2

Voltage

3

Frequency

4

Power Ans: 2

Q. There is 20 volt accross the inductor and 15 volt across the resistance in the a.c. supplied series R-L circuit. What would be the supply voltage? 1

20 volt

2

15 volt

3

25 volt

4

17.5 volt Ans: 3

Q. What is the value of knee voltage of silicon diode? 1

0.3V

2

0.33V

3

0.7V

4

1.1V Ans: 3

Q. Estimated time period of a pendulum of length 0.2m is closer to is 1

.5 sec

2

1 sec

3

2 sec

4

None of these Ans: 2

Q. Which of the following light waves is outside the visible spectrum? 1

Violet

2

Blue

3

Yellow

4

Ultraviolet Ans: 4

Q. A periscope works by the principle of 1

Refraction

2

Total Internal reflection

3

Diffraction

4

Reflection and refraction Ans: 2

Q. A falling drop of rain water acquires the spherical shape due to 1

Surface Tension

2

Gravitational force

3

Atmospheric pressure

4

Viscosity Ans: 1

Q. Each of 3 capacitors of capacity C are connected together in series. This combination is added in paralled to a capacitor of capacity C. Resultant capacity will be 1

C

2

3C

3

4C

4

4C/3 Ans: 4

Q. A boy has five resistance of 1/5 ohm each. The maximum resistance that can be formed with them is 1

0.5 ohm

2

1 ohm

3

1/25 ohm

4

1/5 ohm Ans: 2

Q. For generating large currents on D.C. generators which winding is generally preferred? 1

Progressive wave winding

2

Lap winding

3

Retrogressive wave winding

4

Current depends on design Ans: 2

Q. Calorie value is the least of the following materials 1

Coal gas

2

Producer gas

3

Steam fiery gas

4

Oil gas Ans: 2

Q. Which of the following is not a property of difference amplifier? 1 Capacitor is used in it 2 It is used to compare two signals 3 Difference amplifier yields more than the direct couple ampliier 4 Frequency of difference amplifier remains flat from zero to high frequency Ans: 1 Q. Germanium possesses 1 Two valence electrons 2 Three valence electrons 3 Four valence electrons 4 Five valence electrons Ans: 3 Q. Moisture can be removed from lubricating oil using 1

Tubular centrifugal

2

Clarifier

3

Sparkler filter

4

Vacuum leaf filter Ans: 1

Q. The information is sent by CW transmitter by 1

Changing the audio frequency

2

Interrupting radio signal

3

Using microphone

4

Using camera Ans: 1

Q. If one cylinder of a diesel engine receives more fuel than the others, then for that cylinder the -1

Exhaust will be smokey

2

Piston rings would stik into piston grooves

3

Scavenging occurs

4

Engine starts overheating Ans: 1

Q. What is the proper use of signal generator? 1

Designing

2

Testing

3

Repairing

4

All of the Above Ans: 4

Q. Which type of oscillator is most stable in simple circuit? 1

Crystalline oscillators

2

Clapp oscillators

3

Colepitts oscillator

4

Armstong oscillator Ans: 1

Q. What is the S. I. unit of magnetic flux density? 1

Gauss

2

Tesla

3

Oersted

4

Weber Ans: 2

Q. What are Ferrites? 1 Magnetic but have low resistance 2 Magnetic but have high resistance 3 Non-magnetic with low resistance 4 Non-magnetic with high resistance Ans: 2 Q. An electronics circuits in which different components such as Diode, Resistor and Capacitor etc. are connected separately is called 1

Chassis

2

Printed board

3

Integrated circuit

4

Discrete circuit Ans: 3

Q. Selectivity of the receiver can be increased by which of the following? 1

By using more tuned circuit

2

By decreasing number of tuned circuit

3

By using loudspeaker

4

By increasing gain of the receiver Ans: 4

Q. In case of ball bearings, which part is made harder than others 1

Ball

2

Outer race

3

Inner race

4

All are made equally hard Ans: 4

Q. Which of the following motors is preferred when quick speed reversal is the main consideration? 1

Squirrel cage induction motor

2

Wound rotor induction motor

3

Synchronous motor

4

D. C. motor Ans: 4

Q. Motor-generator set for D. C. arc welding has generator of -

1

Series type

2

Shunt type

3

Differentially compound type

4

Level compound type Ans: 3

Q. ...signal will become zero when the feedback signal and reference signs are equal. 1

Input

2

Actuating

3

Feedback

4

Reference Ans: 2

Q. The capacitance, in force-current analogy, is analogous to 1

Momentum

2

Velocity

3

Displacement

4

Mass Ans: 4

Q. Co-efficient of velocity as compared to the coefficient of discharge is 1

Less

2

More

3

Equal

4

Less or more depending on flow Ans: 2

Q. A. C. servomotor is basically a/an ... 1 Universal motor 2 Single phase induction motor 3 Two phase induction motor 4 Three phase induction motor Ans: 3 Q. In resistance heating, highest working temperature is obtained from heating elementsmade of... 1

Nickel and copper

2

Nichrome

3

Silicon carbide

4

Silver Ans: 2

Q. Among the following statement which is the false? 1 Only minority impurities are added in a junction diode 2 Higher temperature increases the leakage current of diode 3 A simple zener diode works when connected between anode to cathode 4 Zener is mostly used in voltage regulator

Ans: 1 Q. In steam turbine the action of steam is 1

Stable

2

Dynamic

3

Stable and dynamic

4

Neither stable nor dynamic Ans: 2

Q. Protein is not available in which of the following? 1

Meat

2

Milk

3

Rice

4

Pulse Ans: 3

Q. Lever functions on which of the following principles? 1

Crank-shaft

2

Joining rod

3

Crank pin

4

Cross head Ans: 1

Q. What would be the expenditure in 30 days at the rate of 50 paise per unit, if a bulb of 100 W is used five hours per day? 1

Rs. 10.50

2

Rs. 8.50

3

Rs. 7.50

4

Rs. 9.50 Ans: 3

Q. What is the frequency of the receiver? 1

488 kHz

2

445 kHz

3

455 kHz

4

456 kHz Ans: 4

Q. A diode.... 1 Functions only in one direction 2 Functions in both the directions 3 Does not function at all 4 It gets damaged, when voltage is applied Ans: 1 Q. What is the unit of electrical energy? 1

Ampere

2

Volt

3

Watt

4

Kilowatt-hour Ans: 4

Q. How will a red flower appear, if it is seen through a green glass? 1

Red

2

Brown

3

White

4

Green Ans: 2

Q. Which one of the following allotropes of carbon is used for cutting and drilling? 1

Diamond

2

Graphite

3

Activated carbon

4

Carbon black Ans: 1

Q. Which of the following is used in semi-conductors? 1

Aluminium

2

Copper

3

Silicon

4

None of these Ans: 3

Q. The blue colour of the clear sky is due to 1

Diffraction of light

2

Dispersion of light

3

Reflection of light

4

Refraction of light Ans: 2

Q. In amplitude modulation 1 Amplitude of the carrier is kept constant 2 Change occurs in carrier frequency 3 Amplitude is varied according to the instaneous value of modelling wave 4 None of these Ans: 3 Q. While checked with a multimeter, an open resistor reads 1

Zero

2

Infinite

3

High but within tolerance.

4

Low but not zero Ans: 2

Q. Pulley in a belt drive acts as 1

Cylindrical pair

2

Turning pair

3

Rolling pair

4

Sliding pair Ans: 1

Q. Minority carrier in P-type semiconductor is 1

Free electrons

2

Free holes

3

Holes and electrons both

4

Holes minus electrons Ans: 2

Q. Which of the following can be used to control the speed of a D. C. motor? 1

Thermistor

2

Thyristor

3

Thyratron

4

Transistor Ans: 2

Q. To convert moving coil galvanometer into an ammeter, which of the following methods is used? 1

Small resistance in series

2

Small resistance in parallel

3

High resistance in series

4

High resistance in parallel Ans: 2

Q. When the load is above ....., a synchronous motor is found to be more economical. 1

2 KW

2

20 KW

3

50 KW

4

100 KW Ans: 3

Q. Transistors used in electronic equipments are mostly made of 1

Silver

2

Copper

3

Silicon

4

Carbon Ans: 3

Q. Which of the following is a unit of angle measurement? 1

Hour

2

Second

3

Millimeter

4

None of these Ans: 2

Q. Find the incorrect one 1 Hertz is used to measure frequency. 2 Kelvin is used to measure temperature. 3 Bel is used to measure atmospheric pressure. 4 ohm is used to measure electrical resistance. Ans: 3 Q. If the radius of the earth were to shrink by 1 %, its mass remaining the same, the value of 'g' on the earth's surface would 1

increase by 0.5%

2

increase by 2%

3

decrease by 0.5%

4

decrease by 2% Ans: 2

Q. Which of the statements is NOT correct? 1 The velocity of sound in air increases with the increase of temperature 2 The velocity of sound in air is independent of pressure 3 The velocity of sound in air decreased as humidity increases 4 The velocity of sound in air is not affected by the change in amplitude and frequency Ans: 3 Q. Diffusion of light in the atmosphere takes place due to 1

Carbon dioxide

2

Dust particles

3

Helium

4

Water vapours Ans: 2

Q. Consider the following statements: A 4-wheel vehicle moving a sharp circular path at high speed will 1. Overturn about its outer wheels 2. Overturn about its inner wheels 3. Skid outwards 4. Skid inwards Which of these statements are correct? 1

1&3

2

2&4

3

2&3

4

1&4 Ans: 3

Q. The power of lens is - 2D. What is its focal length? 1

2m

2

0.5m

3

1.0m

4

0.5m Ans: 4

Q. X-rays comprise of: 1 Electrons only 2 Protons only

3 Neutrons only 4 Electromagnetic radiations Ans: 4 Q. Which one of the following is a vector? 1 Kinetic energy 2 Pressure 3 Rate of change of momentum 4 Density Ans: 3 Q. One complete set of positive and negative values of an alternating quantity is known as a 1

Phase

2

Time Period

3

Frequency

4

Cycle Ans: 4

Q. Which of the following is an example of class - I Lever? 1

Pliers

2

Nut Cracker

3

Tongs

4

All of the Above Ans: 1

Q. The special filters used to reduce pollutants from the exhaust of a car are called 1

Water Jacket

2

Exhaust Manifold

3

Baffle plate

4

Catalytic Converter Ans: 4

Q. If two electrically charged bodies are connected by a wire, then the electric current will not flow if 1

Both have the same capacity

2

Both have the same temperature

3

Both have the same potential

4

None of these Ans: 3

Q. The colour of light which travels through glass with the minimum speed is 1

Red

2

Yellow

3

Green

4

Violet Ans: 2

Q. The device used for converting A. C. from higher voltage to lower voltage or vice versa is

called 1

Transmitter

2

Commutator

3

Transformer

4

Generator Ans: 3

Q. If the linear momentum of a particle is doubled, then its kinetic energy will be 1

Doubled

2

Quadrupled

3

Halved

4

None of these Ans: 2

Q. Watt-hour is the unit of 1

Energy

2

Power

3

Potential

4

Current Ans: 1

Q. Which device mixes air and petrol (gas) for the internal combination engine? 1

Carburetor

2

Choke

3

Crankshaft

4

Cylinder Ans: 4

Q. The black hole theory was discovered by 1

S. Chandrashekhar

2

Har Gobind Khorana

3

C. V. Raman

4

S. Ramanujan Ans: 1

Q. It is difficult to magnetise steel because of its 1

Low permeability

2

High retentivity

3

High permeability

4

High density Ans: 1

Q. In electric machines, laminated cores are used with a view to reduce the 1

Friction loss

2

Copper loss

3

Eddy current loss

4

Hysteresis loss

Ans: 3 Q. In DC generators, the brushes are always placed 1 Along the Geometric Neutral Axis (GNA) 2 Along the Magnetic Neutral Axis (MNA) 3 Perpendicular to MNA 4 Perpendicular to GNA Ans: 2 Q. Critical resistance of a DC generator RC is 1 Inversely proportional to speed 2 Proportional to speed 3 Inversely proportional to the square of speed 4 Proportional to the square of speed Ans: 1 Q. If the current and the voltage are out of phase by 90 degree, then the power is 1

Minimum

2

Maximum

3

1.1 VI

4

Zero Ans: 4

Q. Megger is an instrument to measure 1

Very low resistance

2

Insulation resistance

3

Q of a coil

4

Inductance of a coil Ans: 2

Q. The forward resistance of a diode is 1

Zero

2

Infinity

3

Very small

4

Very large Ans: 1

Q. For lubricating roller bearing, lubricant generally required is 1

Semi-solid

2

Solid

3

Liquid

4

None of the above Ans: 1

Q. Which type of reaction produces the most harmful radiation? 1

Fusion reaction

2

Chemical reaction

3

Fission reaction

4

Photo-Chemical reaction Ans: 3