If a source emitting waves of frequency f moves towards an observer with a velocity `(v)/(4)` and the observer moves away from the source with a velocity `(v)/(6)`, the apparent frequency as heard by the observer will be (v=velocity of sound)

Options

A. `14/15f`
B. `14/9f`
C. `10/9f`
D. `2/3f`

Answer

c

Explanation

When source and observer both are moving in the
same direction and observer is ahead of source, then
apparent frequency
`f' = (v-v_o)/(v-v_(s))f=(v-v/6)/(v-(v)/4)=((5v)/6)/((3v)/4) f = 10/9 f`