question_answer

Two engines pass each other moving in opposite directions with uniform speed of 30m/s. One of them is blowing a whistle of frequency 540 Hz. Calculate the frequency heard by driver of second engine before pass each other. Speed sound is 330 m/sec.                                                                                                                         [JEE ONLINE 09-04-2016]

A)  540 Hz

B)                  648 Hz

C)  270 Hz            

D)       450 Hz

Correct Answer: B

Solution :

[b]