A train has just completed a U-curve in a trach which is a semi circle. The engine is at the forward end of the semi circular part of the trach while the last carriage is at the rear end of the semi circular track. The driver blows a whistle of frequency 200 Hz. Velocity of sound is `340(m)/(s)`. Then the apparent frequency as observed by a passenger in the middle of the train, when the speed of the train is 30 m/s, is

Options

A. 181 Hz
B. 200 Hz
C. 188 Hz
D. 210 Hz

Answer

B

Explanation

As passenger is a part of moving train, there is no relative motion between source and listener. Therefore `,n.=n=200 Hz`