set 6 MCQ Questions & Answers Detailed Explanation

Question : 1

Which of the following statements is correct ?

a) Frequency of ultrasonic waves is of the same order as that of X-rays

b) Ultrasonic waves can travel in vacuum

c) Wavelength of ultrasonic waves is of the same order as that of microwaves

d) Speed of ultrasonic waves is of the same order as that of light

Question : 2

What is the effect of humidity on sound waves when humidity increases?

a) Speed of sound waves remains same

b) Speed of sound waves is more

c) Speed of sound waves is less

d) Speed of sound waves becomes zero

Question : 3

How much should minimum distance be between the source of sound and reflecting surface, so that an echo can be heard clearly?

a) 17 metre

b) 24 metre

c) 10 metre

d) 30 metre

Question : 4

Some common mediums in which the speed of sound waves is measured are mentioned below?

1. Air
2. Steel
3. Copper
4. Water

a) 1 < 4 < 3 < 2

b) 1 < 4 < 2 < 3

c) 4 < 1 < 2 < 3

d) 4 < 1 < 3 < 2

Question : 5

Consider the figures of a metal ball and a metal ring given below. The metal ball can just pass through the hole of a metal ring formed out of a strip. When the ball is heated it gets stuck. But when the metal is heated

a) The ball gets stuck because of the diameter of the hole decrease on expansion

b) The ball will still pass through because the hole diameter does not change

c) The ball can still pass through the ring as diameter expands on heating

d) The ball will pass through because there is no change in the ring