Physics · NDA previous year questions

Statement II : Due to heating, water of crystallization of crystal is lost.

1. A.Both the statements are individually true and Statement II is the correct explanation of Statement I
2. B.Both the statements are individually true but Statement II is not the correct explanation of Statement I
3. C.Statement I is true but Statement II is false
4. D.Statement I is false but Statement II is true

Statement I : Water is a high boiling point liquid. Statement II : Hydrogen bonding in water is responsible for high boiling point of water.

1. A.Both the statements are individually true and Statement II is the correct explanation of Statement I
2. B.Both the statements are individually true but Statement II is not the correct explanation of Statement I
3. C.Statement I is true but Statement II is false
4. D.Statement I is false but Statement II is true

Statement I : Convex mirror is used as a driver mirror. Statement II : Images formed by convex mirror are diminished in size.

1. A.Both the statements are individually true and Statement II is the correct explanation of Statement I
2. B.Both the statements are individually true but Statement II is not the correct explanation of Statement I
3. C.Statement I is true but Statement II is false
4. D.Statement I is false but Statement II is true

Statement I : Bats can catch their prey in the darkness of night. Statement II : Bats can produce and also detect ultrasound.

1. A.Both the statements are individually true and Statement II is the correct explanation of Statement I
2. B.Both the statements are individually true but Statement II is not the correct explanation of Statement I
3. C.Statement I is true but Statement II is false
4. D.Statement I is false but Statement II is true

A refracting telescope consists of

1. A.one concave mirror and one convex lens
2. B.two convex lenses of equal focal length
3. C.two concave mirrors of different focal lengths
4. D.two convex lenses of unequal focal lengths

Two similarly charged bodies are kept 5 cm apart in air. If the second body is shifted away from the first by another 5 cm, their force of repulsion will be

1. A.doubled
2. B.halved
3. C.quadrupled
4. D.reduced to one-fourth

A glass of water does not turn into ice as it reaches 0 °C. It is because

1. A.water does not solidify at 0 °C
2. B.a certain amount of heat must be supplied to the glass of water so as to solidify
3. C.a certain amount of heat must be taken out from the glass of water so as to solidify
4. D.water solidifies at 0 K only

The main power supply in India is at 220 V, whereas that in the US is at 110 V. Which one among the following statements in this regard is correct?

1. A.110 V is safer but more expensive to maintain
2. B.110 V is safer and cheaper to maintain
3. C.110 V leads to lower power loss
4. D.110 V works better at higher latitudes

1. A.Option A
2. B.Option B
3. C.Option C
4. D.Option D

The penetrating power of X-rays can be increased by

1. A.increasing the current in the filament
2. B.decreasing the potential difference between the cathode and the anode
3. C.decreasing the current in the filament
4. D.increasing the potential difference between the cathode and the anode

1. A.$AB$ and $BC$
2. B.$BC$ and $DE$
3. C.$CD$ and $DE$
4. D.$DE$ and $AB$

Body A of mass $2\mathrm{kg}$ and another body B of mass $4\mathrm{kg}$ and of same material are kept in the same sunshine for some interval of time. If the rise in temperature is equal for both the bodies, then which one among the following in this regard is correct?

1. A.Heat absorbed by B is double because its mass is double
2. B.Heat absorbed by A is double because its mass is half
3. C.Heat absorbed by both A and B is equal because the quantity of heat absorbed does not depend upon mass
4. D.Heat absorbed by B is four times than the heat absorbed by A because the quantity of heat absorbed is proportional to square of the mass

Which one among the following is not produced by sound waves in air?

1. A.Polarization
2. B.Diffraction
3. C.Reflection
4. D.Refraction

A body attached to a spring balance weighs 10 kg on the Earth. The body attached to the same spring balance is taken to a planet where gravity is half that of the Earth. The balance will read

1. A.20 kg
2. B.10 kg
3. C.5 kg
4. D.2·5 kg

The resistance of a wire is 10 Ω. If it is stretched ten times, the resistance will be

1. A.1 Ω
2. B.10 Ω
3. C.100 Ω
4. D.1000 Ω

If the focal length of the biconvex lens is 25 cm, then the power of the lens will be

1. A.+4 dioptre
2. B.−4 dioptre
3. C.+0·04 dioptre
4. D.−0·04 dioptre

The thermal conductivity of copper is 4 times that of brass. Two rods of copper and brass having same length and cross-section are joined end to end. The free end of copper is at 0 °C and the free end of brass is at 100 °C. The temperature of the junction is

1. A.20 °C
2. B.40 °C
3. C.60 °C
4. D.10 °C

The torque on a rectangular coil placed in a uniform magnetic field is large when the

1. A.number of turns is large
2. B.number of turns is less
3. C.plane of the coil is perpendicular to the magnetic field
4. D.area of the coil is small

Two thin convex lenses of focal lengths 4 cm and 8 cm are separated by a distance of 4 cm in air. The combination will have the focal length

1. A.4 cm
2. B.8 cm
3. C.12 cm
4. D.32 cm

For which among the following house appliances, magnet is an essential part?

1. A.Calling bell
2. B.Fan
3. C.Washing machine
4. D.All of the above

To obtain the powerful parallel beams of light from a vehicle’s headlight, one must use

1. A.front surface silvered plane mirror
2. B.back surface silvered plane mirror
3. C.concave mirror
4. D.convex mirror

The common edible mushroom is a

1. A.mass of fungal spores
2. B.type of hypha
3. C.tightly packed mycelium
4. D.structure used for producing asexual spores

Birds like Flamingos can stand on one leg. Which among the following statements relating to this is/are correct ? 1. By standing on one leg Flamingos can conserve body heat and energy because they can reduce great deal of surface area for the loss of heat. 2. By standing on one leg, one Flamingo makes a courtship display, which is a part of ritual prior to reproduction. Select the correct answer using the code given below :

1. A.1 only
2. B.2 only
3. C.Both 1 and 2
4. D.Neither 1 nor 2

Two copper wires A and B of length $l$ and $2l$ respectively, have the same area of cross-section. The ratio of the resistivity of wire A to the resistivity of wire B is

1. A.4
2. B.2
3. C.1
4. D.1/2

The position - time (x - t) graph for motion of a body is given below : Which one among the following is depicted by the above graph ?

1. A.Positive acceleration
2. B.Negative acceleration
3. C.Zero acceleration
4. D.None of the above