set 15 MCQ Questions & Answers Detailed Explanation

Question : 1

Assertion (A):
A jet aircraft moving at mach number equal to 1 travels faster at an altitude of 15 km than while moving at mach number equal to 1 near the sea level.
Reason (R):
The velocity of sound depends on the temperature of the surrounding medium.
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

Which one of the colours has the longest wavelength?

a) Blue

b) Yellow

c) Green

d) Red

Question : 3

A well cut diamond appears bright because

a) of the total internal reflection

b) of reflection of light

c) of dispersion of light

d) of refraction of light

Question : 4

The technique used to transmit auto signals in television broadcasts is

a) Pulse Code Modulation

b) Frequency Modulation

c) Amplitude Modulation

d) Time Division Multiplexing

Question : 5

In scattering of light phenomenon, light falls on tiny particles absorbed by these tiny particles. Then these particles re-emit light in all directions.

1. Intensity of scattered light, $I ∝ 1/λ^4$
2. Greenish-blue appearance of sea water is due to scattering of light
3. In a clear atmosphere of the earth, red colour scatters more than blue colour.

a) 1 and 3

b) 1 and 2

c) 2 and 3

d) 1, 2 and 3

Question : 6

Assertion (A) :
A jet aircraft moving at Mach Number equal to 1 travels faster at an altitude of 15 km than while moving at Mach Number equal to 1 near the sea level.
Reason (R) :
The velocity of sound depends on the temperature of the surrounding medium.

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

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

c) A is true but R is false

d) A is false but R is true