A train is moving with a unifrom speed of 33 m/ s and an observer is approaching the train with the same speed. If the train blows a whistle of frequency 1000 Hz and the velocity of sound is 333 m/s, then the apparent frequency of the sound that the observer hear is

Options

A. 1220 Hz
B. 1099 Hz
C. 1110 Hz
D. 1200 Hz

Answer

A

Explanation

Here, velocity of the source, `u_(s) = 33 m//s`
Velocity of the observer, `u_(0)=33 m//s)`
Now, velocity of sound, V = 333 m/s
As the source and the observer are approching each other, so , apparent frequency,
`n.=(v+u_(0))/(v-u_(2)) cdot n =(333+33)/(333-333)xx1000 = 1220 ` Hz The option (A) is correct.