CBSE Class 8 - Science - CH 13 - Sound (Question Bank) (#cbseNotes)

SOUND

Question Bank

Very Short Answer Type Questions

Q1: Define vibration.

Q2: What is meant by oscillatory motion?

Q3: How is sound produced?

Q4: Can sound travel in vacuum?

Q5: Define amplitude.

Q6: Define frequency.

Q7: Define 1 hertz.

Q8: What is audible range of sound?

Q9: In humans, sound is produced by _______

Q10: Name the equipment which works at frequencies greater than 20,000 Hz.

Q11: What is noise ?

Q12: In which unit loudness is expressed?

Q13: What is the necessary condition for sound propagation?

Q14: What are ultrasonic sounds?

Q15: Name the SI units of

(i) time period

(ii) frequency.


Q16: In which state of matter does sound travel the

(i) slowest

(ii) faster?

Q17: What is outer part of ear is called ?

Q18: What happens to sound when it strikes a surface?

Q19: Name the two animals that use echolocation to guide themselves.

Short Answer Type Questions

Q20: How can we control the sources of noise pollution?

Q21: Can you hear the sound on the moon? Explain.

Q22: Why do we hear the thunder a little after we see the flash of lightning?

Q23: What is relation between loudness of sound and amplitude ?

Q24: A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency.

Q25: List sources of noise pollution in your surroundings.

Q26: Define the term 'quality of sound'?

Q27: Why do the walls, floor and ceilings are covered by sound absorbing materials in cinema hall and auditorium?

Q28: Give reason:

(i) During a thunderstorm, we see the lightning first and then hear the thunder.

(ii) We do not hear the supersonic jets when they approach us, but hear a sudden boom after it has passed away.

Q29: The frequency of a given sound is 1.5 KHz. How many vibrations is it completing in one second ?

Q30: How is that you can hear a friend talking in another room without seeing him?

Long Answer Type Questions

Q31: (a) What is SONAR ?

(b) What is the basic principle of its working?

(c) Explain its use.

Q32: Explain how sound is produced by each of the following types of musical instruments.

(i) Wind instruments.

(ii) Stringed instruments.

(iii) Percussion instruments.

Q33: Sound produced by a mosquito is quite different from the roar of a lion. Explain.

Q34: (a) Name the properties of sound which is

(i) similar to the property of light.

(ii) different from that of light

(b) Why do some people have hearing impairment ? How do they communicate with others?

Q35: Write differences between musical sound and noise.

Q36: How do we hear sound? Explain with the diagram.

Q37: How is the human voice produced? Explain.

Q38: What do you understand by the term noise pollution? What are the different various ways of minimising noise pollution?

Q39: Suppose your parents want to buy a house. They have chosen two houses; one on the road side and the other three lanes away from the road side. Which house will you prefer and why?