Grade 9 Physics – Propagation of Sound Waves Question Bank with Answers

PROPAGATION OF SOUND WAVES

QUESTION BANK WITH ANSWERS

ONE MARK QUESTIONS

1.​ What is sound?
Answer: Sound is a form of energy produced by vibrating bodies.

2.​ What is required for the production of sound?
Answer: Vibrations are required for the production of sound.

3.​ Name the device used to produce sound in experiments.
Answer: Tuning fork.

4.​ Can sound travel through vacuum?
Answer: No.

5.​ Which wave is sound wave?
Answer: Longitudinal wave.

6.​ What are compressions?
Answer: Regions where particles are crowded together.

7.​ What are rarefactions?
Answer: Regions where particles are spread apart.

8.​ Define frequency.
Answer: Number of vibrations per second is called frequency.

9.​ What is the SI unit of frequency?
Answer: Hertz (Hz).

, 10.​ Define time period.
Answer: Time taken for one complete vibration.

11.​ Write the relation between frequency and time period.
Answer: f = 1/T

12.​ Define amplitude.
Answer: Maximum displacement of a vibrating particle from its mean
position.

13.​ State the unit of wavelength.
Answer: metre (m)

14.​ Write the wave equation.
Answer: v = fλ

15.​ What is audible range for humans?
Answer: 20 Hz to 20,000 Hz.

16.​ What is infrasonic sound?
Answer: Sound with frequency below 20 Hz.

17.​ What is ultrasonic sound?
Answer: Sound with frequency above 20,000 Hz.

18.​ Which medium carries sound fastest?
Answer: Solids.

19.​ What is SONAR?
Answer: Sound Navigation And Ranging.