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The disc of siren has n holes and the fr...

The disc of siren has n holes and the frequency of its rotation is 300 rpm. It produces a notes of wavelength 2.4 m. If the velocity of sound in air is 360 m/s, then the value of n will be

A

30

B

34

C

12

D

15

Text Solution

Verified by Experts

The correct Answer is:
A
Time taken for one rotation
`=(1)/(300)min=1/5S`
Frequency, `f=(v)/(lamda)=360/24=150Hz`
Time taken to travel from one hole to other hole
`=1/150sec`
`(1)/(5n)=(1)/(150)impliesn=30`
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