set 4 MCQ Questions & Answers Detailed Explanation

Question : 1

The colour of an opaque object is due to the colour it

a) Reflects

b) Refracts

c) Absorbs

d) Scatters

Question : 2

Which of the following statements is/are correct about sound?

1. Sound is produced by a vibrating body.
2. Sound needs a medium for propagation.
3. If 2 sounds are equally loud, then their pitch will also be equal.

a) 1, 2 and 3

b) 1 and 3

c) 3 only

d) 1 and 2

Question : 3

Match list I with list II and select the correct answer using the codes given below the lists.

a) A – 3, B – 4, C – 2, D – 1

b) A – 2, B – 3, C – 4, D – 1

c) A – 2, B – 1, C – 4, D – 3

d) A – 3, B – 4, C – 1, D – 2

Question : 4

Consider the following statements : Sound waves can undergo

1. reflection
2. refraction
3. interference

a) 2 and 3 only

b) 1 and 2 only

c) 1 and 3 only

d) 1, 2 and 3

Question : 5

A periodic wave is produced on a stretched string. Note the following quantities associated with the wave and the string

1. frequency
2. tension in the string
3. wavelength
4. linear density of the string

a) 1 and 2

b) 1 only

c) 3 and 4

d) 1, 2, 3 and 4

Question : 6

Consider the following statements.

1. The heart vibrates at infrasonic.
2. The speed of sound is more in gas than in liquid and solid.
3. Mach number is used to describe the speed of sound.
4. Ultrasonic sound has frequency more than 20,000 Hz.

a) 2, 3 and 4 are correct

b) 1, 3 and 4 are correct

c) 1, 2 and 3 are correct

d) 1, 2 and 4 are correct