set 14 MCQ Questions & Answers Detailed Explanation

Question : 1

Assertion (A):
The boiling point of water decreases as the altitude increases.
Reason (R):
The atmospheric pressure increases with altitude.
Code

a) Both (A) and (R) are true, but (R) is not the correct explanation of (A)

b) (A) is true, but (R) is false

c) Both (A) and (R) are true and (R) is the correct explanation of (A)

d) (A) is false, but (R) is true

Question : 2

The acronym for LASER is

a) Low Amplitude Short Energy Radiation

b) Light Amplification by Stimulated Emission of Radiation

c) Low Amplitude Stimulated Emission of Radiation

d) Light Amplification by Short Energy Radiation

Question : 3

Which of the following atmospheric layers is responsible for the deflection of radio waves?

a) Mesosphere

b) Stratosphere

c) Troposphere

d) Ionosphere

Question : 4

If a car is moving towards you with its horn sounding, you hear a higher pitch than you would hear if the car were at rest. This is because:

a) you receive successive crests more frequently even though the wave itself is unchanged

b) the waves travel faster

c) successive crests produced by the horn are closer to each other

d) the motion of the car raises the frequency of the horn

Question : 5

The marching soldiers break steps while crossing a bridge because of

a) echo

b) damped oscillations

c) resonance

d) reverberation

Question : 6

Consider the following statements :

1. 1 gram of water at 100°C and 1 gram of steam at 100°C contain same amount of heat.
2. 1 m3 of dry air is heavier than 1 m3 of humid air.
3. Density of a substance in C.G.S. system is numerically equal to its specific gravity.

a) 1 and 3

b) 3 only

c) 1 only

d) 2 and 3