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. (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 the vibration is large, the 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 the pitch. (T/F)
$(f)$. An unwanted or unpleasant sound is termed music. (T/F)
$(g)$. Noise pollution may cause partial hearing impairment. (T/F)

AcademicPhysicsNCERTClass 8

$(a)$. Sound cannot travel in vacuum. $(T)$

Explanation:

Sound is a longitudinal wave that requires a medium to travel$(solid,\ liquid,\ gas)$. A sound wave can not travel in vacuum.


$(b)$. The number of oscillations per second of a vibrating object is called its time period. $(F)$

Explanation:

The number of oscillations per second of a vibrating object is called its frequency.


$(c)$. If the amplitude of vibration is large, sound is feeble. $(F)$

Explanation:

If the amplitude of the vibration is large, the sound is loud.


$(d)$. For human ears, the audible range is 20 Hz to 20,000 Hz. $(T)$

Explanation:

Sound waves below 20 Hz or above 20,000 Hz are beyond the audible range of the human ear.


$(e)$. The lower the frequency of vibration, the higher is the pitch. $(F)$

Explanation:

The lower the frequency of vibration, the lower the pitch as the pitch of a sound wave is directly proportional to the frequency of a sound wave.


$(f)$. Unwanted or unpleasant sound is termed as music. $(F)$

Explanation:

An unwanted or unpleasant sound is termed noise.


$(g)$. Noise pollution may cause partial hearing impairment. $(T)$

Explanation:

Noise pollution is caused by high noise levels. It causes several adverse effects in humans. Noise pollution can lead to hearing impairment, high blood pressure, high-stress levels, etc.

raja
Updated on 10-Oct-2022 13:25:05

Advertisements