In the following statements, tick T against those which are true, and F against those which are false:
(a) Sound cannot travel in vacuum. (T/F)
(b) The number of oscillations per second of a vibrating object is called its time period. (T/F)
(c) If the amplitude of vibration is large, sound is feeble. (T/F)
(d) For human ears, the audible range is 20 Hz to 20,000 Hz. (T/F)
(e) The lower the frequency of vibration, the higher is the pitch. (T/F)
(f) Unwanted or unpleasant sound is termed as music. (T/F)
(g) Noise pollution may cause partial hearing impairment. (T/F)
Answer
(a) True
Sound needs a medium to travel. Since vacuum does not have a medium, sound cannot travel through vacuum.
(b) False
The number of oscillations per second of a vibrating object is called its frequency.
Time period is the time taken by the wave to one complete oscillation
(c) False
Loudness of sound is proportional to the amplitude.
If the amplitude is large, sound would be loud
If the amplitude is small, sound produced is feeble
(d) True
Human ears can hear a sound whose frequency range is between 20 Hz and 20,000 Hz.
(e) False
Pitch of sound is proportional to the frequency.
If frequency is low, sound would be of low pitch.
(f) False
Unwanted or unpleasant sound is termed as noise.
Sounds which is pleasant to hear is called Music
(g) True
Presence of Excessive sounds or Unwanted Sounds in our environment is called Noise Pollution
If a person hears the unwanted sound for a long time it may lead to partial hearing impairment
