WBCS Prelims and Mains MCQs on General Science (Physics) P12

<< Prev PHYSICSNext >>

---

Page 12

1532111. When the water cools from 7°C to 0°C

A

It first contracts and then expands

B

It first expands and then contracts

C

It contracts only

D

It expands only

A

Correct Answer: A. It first contracts and then expands

1574112. X-rays are

A

Electromagnetic wave of long wavelength

B

Electromagnetic wave of short wavelength

C

Electromagnetic wave

D

None of the above

B

Correct Answer: B. Electromagnetic wave of short wavelength

1591113. Solar energy is produced by the process of

A

Explosion

B

Contraction

C

Fusion

D

Fission

C

Correct Answer: C. Fusion

1585114. In a p-type semiconductor, which is the main carrier of electricity?

A

Electrons

B

Negative Ions

C

Positive holes

D

Positive Ions

C

Correct Answer: C. Positive holes

1549115. The surface of the water in a lake is going to freeze. The temperature of water at the bottom is

A

4°C

B

0°C

C

More than 4°C

D

Less than 4°C

A

Correct Answer: A. 4°C

1580116. The temperature of two bodies being equal means

A

Their heat capacities are the same

B

Their specific heats are the same

C

Their heat contents are the same

D

When they are brought in contact there will be no exchange of heat

D

Correct Answer: D. When they are brought in contact there will be no exchange of heat

1515117. An iron ball and a wooden ball of the same mass are released from a height h in air. Neglecting viscous drag of air

A

There is an equal probability for the wooden and iron ball to hit the ground earlier.

B

Both will reach the ground at the same time.

C

The iron ball will hit the ground earlier.

D

The wooden ball will hit the ground earlier

B

Correct Answer: B. Both will reach the ground at the same time.

1465118. Both ends of the tube of a Telescope have

A

Plano-convex lens

B

Piano concave lens

C

Convex lens

D

Concave lens.

C

Correct Answer: C. Convex lens

1496119. A shaving brush is dipped in water. When taken out the hairs of the brush are seen to be drawn together due to

A

the elasticity of the hairs of the brush.

B

the temperature difference between air and water.

C

the surface tension of water.

D

the viscosity of water

C

Correct Answer: C. the surface tension of water.

1611120. The reverberation of sound in a half is due to continued

A

diffraction

B

absorption

C

reflection

D

interference

D

Correct Answer: D. interference

---

<< Prev PHYSICSNext >>