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The driver of a car travelling with spee...

The driver of a car travelling with speed 30 m/sec towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air 330 m/s , the frequency of reflected sound as heard by driver is :

A

555.5 Hz

B

720 Hz

C

500 Hz

D

550 Hz

Text Solution

Verified by Experts

The correct Answer is:
B
f = `(v)/(v - 30 ) f, f.. = (v + 30)/(v) f. `
= `(v + 30)/(v - 30) f = (360)/(300) xx 600 = 720 ` Hz
Correct choice is (b).
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