Home Physics MCQs Physics MCQs with Answers for Competitive Exams

# Physics MCQs with Answers for Competitive Exams

676

### Physics MCQs with Answers for NTS, PPSC, CSS, FPSC, PMS, OTS, PTS Tests and Interviews

This Post contains Physics MCQs with Answers for NTS, PPSC, CSS, FPSC, PMS, OTS, PTS Tests and Interviews. This is the 8th post of Physics Multiple Choice Questions Quiz series. MCQs are taken from Caravan Comprehensive Book. If you want more MCQs of Physics, you can Visit This Post.

## Physics Multiple Choice Questions for Competitive Exams

MCQs are starting from No. 141. For previous Physics MCQs Go Here.

141. During rusting________.

(a) Iron gains weight
(b) Iron‘loses weight
(c) Weight of iron remains unchanged
(d) Iron volatilizes

(a) Iron gains weight

142. When water boils, its temperature________.

(a) Begins to increase
(b) Begins to decrease
(c) Remains constant
(d) Fluctuates

(c) Remains constant

143. Rectifiers are used to convert_______.

(a) DC to AC
(b) AC to DC
(c) High voltage to low voltage
(d) Low voltage to high voltage

(b) AC to DC

144. A needle smeared with vaseline when lowered slowly on the surface of the water in a horizontal position appears to float. The phenomenon is an example of_______.

(a) Capillary action
(b) Surface tension
(c) Osmosis
(d) Archimedes principle

(b) Surface tension

145. Which one of the following statements is correct?
A slab of ice kept in a room _________.

(b) Does not radiate heat but absorbs heat from the surrounding
(c) Radiates heat but absorbs more heat from the surrounding
(d) Radiates heat more than that absorbed by it from the surrounding

(b) Does not radiate heat but absorbs heat from the surrounding

146. The phenomenon of the formation of three-dimensional image by the interference of two light beams from the laser or other coherent sources of light is called:

(a) Opticai photography
(b) X-ray photography
(d) Holography

(d) Holography

147. Paper becomes brittle and yellow with age, Why?

1. The acid content in paper causes brittleness to develop
2. In the presence of visible light, photosensitised oxidation occurs
3. The ultra-violet component of sunlight causes photolysis of cellulose by direct cleavage of the cellulose polymer

(a) 1 and 2
(b) 2 and 3
(c) 1 and 3
(d) 1. 2 and 3

(d) 1. 2 and 3

148. Two cars, passing each other at high speed, are in danger of side swiping because ______.

(a) Of the increase in air pressure in the space between them
(b) Of decrease in the velocity of air molecules between them
(c) Of decrease in air pressure in the space between them
(d) Increase in the velocity of air molecules between them

(c) Of decrease in air pressure in the space between them

149. Which of the following is used as a coolant in nuclear reactors?

(a) Heavy water
(c) Liquid sodium
(d) Graphite

(c) Liquid sodium

150. Which of the following is good nuclear fuel?

(a) Uranium-238
(b) Neptunium-239
(c) Thorium-236
(d) Plutonium-239

(d) Plutonium-239

151. In an atomic explosion, enormous energy is released which is due to the _______.

(a) Conversion of neutrons into protons
(b) Conversion of chemical energy into heat energy
(c) Conversion of chemical energy into nuclear energy
(d) Conversion of mass into energy

(d) Conversion of mass into energy

152. Optic fibres are mainly used for which of the following?

(a) Communication
(b) Weaving
(c) Musical instruments
(d) Food industry

(a) Communication

153. Which of the following take place when the subject speaks untruth while being tested by the polygraph instrument?

1. His blood pressure goes up.
2. His pulse quickens.
3. His skin darkens.
4. He sneezes.

(a) 1 and 2
(b) 3 and 4
(c) 1, 2 and 3
(d) 2, 1 and 3

(a) 1 and 2

154. The following processes take place during the launching of a rocket.

1. Rocketfuel is burnt.
2. Gases are produced.
3. The rocket moves in the forward direction.
4. Gases come out with momentum in the backward direction.
The correct sequential order in which the above processes occur is __________.

(a) 1, 2, 3, 4
(b) 1, 3, 2, 4
(c) 1, 2, 4, 3
(d) 1, 3, 4, 2

(c) 1, 2, 4, 3

155. Aviation fuel for jet aeroplanes consists of purified:

(a) Petrol
(b) Kerosene
(c) Gasoline
(d) Diesel

(b) Kerosene

156. A silver spoon and a book are both at room temperature. The spoon feels colder to the touch because_______.

(a) Of an illusory effect
(b) Silver is an almost pure material
(c) Silver is a very good heat conductor
(d) it is made of a denser material

(c) Silver is a very good heat conductor

157. A liquid rises in a syringe when its piston is pulled up because:-

(a) Of the property of surface tension
(b) 0f capillary action
(c) Of the action of atmospheric pressure
(d) There is a force of cohesion between the liquid molecules and the glass syringe

(c) Of the action of atmospheric pressure

158. A small weight is put on the pressure cooker. It increases the pressure of the steam because:-

(a) The weight is proportionate to the steam required
(b) Area of contact is small
(c) The weight stops the steam from escaping
(d) Of Bernoulli’s principle

(b) Area of contact is small

159. When an electric bulb breaks, there is a mild sang due to ________.

(a) The chemical reaction between the enclosed gases
(b) The compressed gases rushing out suddenly
(c) The air rushing in to fill the evacuated space
(d) None of the above

(c) The air rushing in to fill the evacuated space

160. Kinetic energy depends ________.

(a) On the mass of the moving body
(b) The velocity or speed of the moving body
(c) The pressure of the moving body
(d) Both mass and velocity of the moving body

(d) Both mass and velocity of the moving body