Question

In the following statements, tick $T$ against those which are true, and $F$ against those which are false.
(A) Sound cannot travel in a vacuum. $\left( {T/F} \right)$
(B) The number of oscillations per second of a vibrating object is called its time period. $\left( {T/F} \right)$
(C) If the amplitude of vibration is large, the sound is feeble. $\left( {T/F} \right)$
(D) For human ears, the audible range is $20Hz$ to$20,000Hz$. $\left( {T/F} \right)$
(E) The lower the frequency of vibration the higher is the pitch. $\left( {T/F} \right)$
(F) Unwanted or unpleasant sound is termed as music. $\left( {T/F} \right)$
(G) Noise pollution may cause partial hearing impairment. $\left( {T/F} \right)$

Answer 1

Hint: The above true and false statements will be justified here with the appropriate reason. Questions are based on the different types of pollution and their frequency. Some of them are related to oscillations and amplitude also. Let’s see one by one.

Complete solution
A wave transports its energy employing particle interaction. So the sound wave can’t travel through a medium which is a vacuum. This makes the sound a mechanical wave. Therefore the $Statement{\text{ }}\left( A \right)$ becomes true.
A vibratory object whose range of oscillations per second is understood as its frequency. The time taken to finish one oscillation is called a period of time. Therefore $Statement{\text{ }}\left( B \right)$ becomes false.
Since the loudness of sound and amplitude of vibration both are proportional to each other. So, the sound is loud once the amplitude of vibration is giant. For feeble sound, the amplitude is tiny. Therefore the $Statement{\text{ }}\left( C \right)$ becomes False.
Sounds of all frequencies don't seem to be hearable to human ears. The variety of frequencies that are hearable to human ears is between $20Hz$to$20,000Hz$. Sounds outside these frequencies don't seem to be hearable to human ears.

Therefore the $Statement{\text{ }}\left( D \right)$ becomes True.

The higher the frequency, the higher is the pitch of the sound because the pitch is proportional to its frequency. for top pitched sound, its vibratory frequency is high and for low pitched sound, its vibratory frequency is tiny. Therefore the $Statement{\text{ }}\left( E \right)$ becomes False.
Music may be a melodious and pleasing sound that is pleasant to listen to. Noises are unpleasant sounds. Therefore the $Statement{\text{ }}\left( F \right)$becomes False.
Noises are unwanted and unsightly sounds, which causes temporary hearing disorder once detected endlessly for an extended amount of your time. Therefore the $Statement{\text{ }}\left( G \right)$ becomes True.

Notes: A sound wave could be a longitudinal wave and has all the final properties of waves. Since sound could be a longitudinal wave, it consists of compact regions of matter (compression) and regions of matter that is loosely packed (rarefaction). A sound wave moves through matter rather like a longitudinal wave moves.