A stationary source emits sound waves of frequency 500 HZ. Two observes moving along a line passing through the source detect sound to be of frequencies 480 Hz and 530Hz. Their respective speeds are, in ms^{−1 }(Given speed of sound = 300 m/s)

A stationary source emits sound waves of frequency 500 HZ. Two observes moving along a line passing through the source detect sound to be of frequencies 480 Hz and 530Hz. Their respective speeds are, in ms^{−1 }(Given speed of sound = 300 m/s)

(a)

12, 16

(b)

16, 14

(c)

8 ,18

(d)

12, 18

1 Answer

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Answer Key / Explanation : (d) -

Frequency of sound source (f_{0}) = 500 Hz

When observer is moving away from the source

Apparent frequency f_{1}= 480 = f_{0} … (i)

And when observer is moving towards the source f_{2}= 530 f_{0} …(ii)