wave_mechanics dopplers_effect Question 23
Question: A source of sound S is moving with a velocity 50m/s towards a stationary observer. The observer measures the frequency of the source as 1000 Hz. What will be the apparent frequency of the source when it is moving away from the observer after crossing him ? The velocity of sound in the medium is 350 m/s
[MP PMT 1994]
Options:
A) 750 Hz
B) 857 Hz
C) 1143 Hz
D) 1333 Hz
Show Answer
Answer:
Correct Answer: A
Solution:
By using $ \frac{{n _{\text{approaching}}}}{{n _{\text{receding}}}}=\frac{v+v _{s}}{v-v _{s}} $
Therefore $ \frac{1000}{n _{r}}=\frac{350+50}{350-50} $
Therefore, $ n_{r} = 750 , \text{Hz}.
$
BETA
