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Two aeroplanes A and B are moving toward...

Two aeroplanes A and B are moving towards each other with a speed of 120 m/s. The frequency of the shistle emitted by A is 100 Hz. What is the apparent frequency of the whistle as heard by the captain of plane B?
(Velocity of sound in air = 360 m/s)

A

500 Hz

B

1500 Hz

C

2000 Hz

D

2500 Hz

Text Solution

Verified by Experts

The correct Answer is:
C
As both the source and the observer are moving towards each other, the apparent frequency
`n_(B) = ((V + V_(0))/(V - V_(s))) xx n`
`= ((360 + 120)/(360 - 120)) xx 1000`
`= ((480)/(240)) xx 1000 = 2000 Hz`
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