set 10 MCQ Questions & Answers Detailed Explanation

Question : 1

Twinkling of stars is on account of

a) large size of stars

b) large distance of stars and storms in air

c) small size of stars

d) large distance of stars and fluctuations in the density of air

Question : 2

The temperature of a room is 77°F. What would it be on the Celsius scale?

a) 60°C

b) 25°C

c) 45°C

d) 350°C

Question : 3

Assertion (A):
In a motion picture, usually 24 frames are projected every second over the whole length of the film.
Reason (R):
An image formed on the retina of eye persists for about 0.1s after the removal of the stimulus.
Code

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

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

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

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

Question : 4

In SONAR, we use

a) infrasonic waves

b) ultrasonic waves

c) radio waves

d) audible sound waves

Question : 5

Consider the following statements :

1. Fahrenheit is the smallest unit measuring temperature.
2. Fahrenheit was the first temperature scale used for measuring temperature.
3. The temperature at which Centigrade and Fahrenheit thermometers read the same is – 40°.

a) 2 and 3

b) 1 and 3

c) 1 and 2

d) 1, 2 and 3

Question : 6

Rainbow is produced when Sunlight falls on drops of rain, which of the following physical phenomena are responsible for this?

1. Dispersion
2. Refraction
3. Internal reflection

a) 1 and 3

b) 2 and 3

c) 1 and 2

d) All of the above