set 15 MCQ Questions & Answers Detailed Explanation

Question : 1

What is the use of thermostat?

a) To increase the temperature

b) To maintain the temperature

c) To measure the temperature

d) To convert heat into electricity

Question : 2

The standing wave pattern along a string of length 60 cm is shown in the above diagram. If the speed of the transverse waves on this string is 300 m/s, in which one of the following modes is the string vibrating ?

a) First overtone

b) Fundamental

c) Second overtone

d) Third overtone

Question : 3

A metal sheet with a circular hole is heated. The hole

a) remains of the same size

b) gets larger

c) gets smaller

d) gets deformed

Question : 4

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 : 5

Which one of the colours has the longest wavelength?

a) Blue

b) Yellow

c) Green

d) Red

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.
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