SOUND T & F ICSE CLASS 8

SOUND FILL IN THE BLANKS AND NOTES

SOUND MCQ

Write True Or False

1. Sound waves travel faster in air than in water.

2. Sound waves do propagate in vacuum.

3. The unpleasant sounds are called noises.

4. The amplitude of a sound depends upon the force applied in vibrating the sound producing object.

5. Women have loud voice in comparison to men.

Answers

Write True Or False

1. False

2. False

3. True

4. False

5. False

WORKSHEET

1. Write true or false for each statement

(a) When sound propagates in air, it does not carry energy with it.

Answer. False.

(b) In a longitudinal wave, compression and rarefaction are formed.

Answer. True.

(c) The distance from one compression to nearest rarefaction is called wavelength.

Answer. False.

(d) The frequency is measured in second.

Answer. False.

(e) The quality of a sound depends on the amplitude of wave.

Answer. False.

(f) The pitch of sound depends on frequency.

Answer. True.

(g) Decibel is the unit of pitch of a sound.

Answer. False.

Question 1.

A sound with higher amplitude is a soft sound whereas a sound with lower amplitude is loud.

Answer:

False.

Correct : A sound with higher amplitude is a loud sound whereas a sound with lower amplitude is a soft sound.

Question 2.

The pitch of a sound of string instruments decreases with the decrease in the thickness of the vibrating string.

Answer:

False.

Correct : The pitch of a sound of string instruments decreases with increase in the thickness of the vibrating string.

Question 3.

Pitch of a sound depends on its frequency.

Answer:

True.

Question 4.

The pitch of a stringed instrument depends on the tension in the string.

Answer:

True.

Question 5.

A flute produces sound due to vibration of air column inside it.

Answer:

True.

Question 6.

Music has a disturbing effect on health and behaviour of a person.

Answer:

False.

Correct : Noise has a disturbing effect on health and behaviour of a person.

Question 7.

Sounds below 50 dB cause noise pollution arid are harmful.

Answer:

False.

Correct : Sounds above 80 dB can cause noise pollution and are harmful.

Question 8.

Percussion instruments produce sound due to the vibration of thin metal strips.

Answer:

False.

Correct : Percussion instruments produce sound by a vibrating stretched membrane or by vibration of their whole bodies.