When source of sound moves towards a stationary observer, the wavelength of sound received by him

Options

A. decreases while frequency increases
B. remains the same whereas frequency increases
C. increases and frequency also increases
D. decreases while frequency remains the same

Answer

A

Explanation

`n '=n [(vpm v_(0))/(vpmv_(s))]`
`v_(0) =0`
`n '=n [(v)/(v - v_(s))]`
So frequency increase, wavelength decrease.