A musician using and open flute of length 50 cm produces second harmonic sound waves. A person runs towards the musician from another end of a hall at a speed of 10 km/h. If the wave speed is 330 m/s, the frequency heard by the running person shall be close to :

Options

A. 333Hz
B. 753Hz
C. 500Hz
D. 666Hz

Answer

D

Explanation

Open flute `f_(2)` (second hamonic) `= (2.V)/(2l)=(330)/(1//2)=660Hz`
`f_(apparent) =f_(2)(V + V_(0))/(V) = 660 (1+(10xx(5)/(18))/(330))=660Hz`