Question

True or False

(a) The number of oscillations per second of a vibrating object is called its timeperiod (T/F).
(b) If the amplitude of vibration is large, sound is feeble. (T/F)
(c) The lower the frequency of vibration, the higher is the pitch. (T/F)
(d) Unwanted or unpleasant sound is termed as music. (T/F)
(e) Noise pollution may cause partial hearing impairment. (T/F)

Answer 1

The number of oscillations per second of a vibrating object is known as its frequency. Time period is the time required to complete one oscillation.

Loudness of a sound is proportional to the square of the amplitude of its vibration. When the amplitude of vibration of a sound is large, the sound is very loud. The sound is feeble for small amplitude.

The pitch of a sound is proportional to its frequency. As the frequency of vibration increases, the pitch of the sound also increases and vice versa. A sound is said to be high pitched if its frequency of vibration is high and is low pitched for a small frequency of vibration.

Unwanted or unpleasant sounds are known as noise. Sounds that are melodious and pleasing to ear are known as music.

Unwanted or unpleasant sounds are known as noise. If one is subjected to loud unpleasant sound continuously for a long time, then it may cause temporary hearing impairment.

Answer 2

The answer to the true or false are :

• The number of oscillations per second of a vibrating object is called its time period is false.
• The correct statement will include frequency in place of the time period.
• If the amplitude of vibration is large, the sound is feeble. This statement is false.
• The correct statement will be that for a sound to be feeble, the amplitude has to be small.
• The lower the frequency of vibration, the higher is the pitch. This statement is false.
• The pitch and frequency go hand in hand. The correct statement will be that for a frequency to be lower, the pitch should also be low.
• An unwanted or unpleasant sound is termed music. This is false.
• The correct answer will include noise in place of music.
• Noise pollution may cause partial hearing impairment. This is true.