Fill in the blanks with suitable words.
$(a)$. Time taken by an object to complete one oscillation is called______.
$(b)$. Loudness is determined by the ________ of vibration.
$(c)$. The unit of frequency is _________.
$(d)$. Unwanted sound is called _________.
$(e)$. The shrillness of a sound is determined by the _________ of vibration.

AcademicPhysicsNCERTClass 8

$(a)$. Time taken by an object to complete one oscillation is called $\underline{Time\ period}$.

Explanation:

The movement of an oscillating object from one extreme to another extreme and then back to the initial position is a complete oscillation of the object and the time taken to complete one oscillation is called its time period.


$(b)$. Loudness is determined by the $\underline{Amplitude}$ of vibration.

Explanation:

The loudness of a sound depends on its amplitude. The higher the amplitude of a sound wave, the higher the loudness of the sound.

Therefore, the loudness of a sound wave is determined by the amplitude of the vibration of the sound wave.


$(c)$. The unit of frequency is $\underline{Hertz}$.

Explanation:

The number of vibrations in a second is called the frequency of the sound. The SI unit of frequency is per second or hertz$(Hz)$.


$(d)$. Unwanted sound is called $\underline{noise}$.

Explanation:

Unwanted or unpleasant sounds are sounds that unnecessarily we hear and get irritated. It is called noise.


$(e)$. Shrillness of a sound is determined by the $\underline{frequency}$ of vibration.

Explanation:

Shrillness of a sound is also said pitch of the sound wave. The pitch of a sound is directly proportional to the frequency of the sound wave. That is why the shrillness of a sound wave is determined by the frequency of its vibration.

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

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