Question

A curve is plotted to represent the dependence of the ratio of the received frequency f to the frequency f₀emitted by the source on the ratio of the speed of observer V_ob to the speed of sound V_sound in a situation in which an observer is moving towards a stationary sound source. The curve is best represented by :

• A.
• B.
• C.
• D.

Answer 1

Answer: (A)

Answer 2

f = f₀$\left( 1 + \frac{V_{ob}}{V_{sound}} \right)$

$\frac{f}{f_{0}}\alpha\frac{V_{ob}}{V_{sound}}$ (straights line)

when $\frac{V_{ob}}{V_{sound}}$ = 0; $\frac{f}{f_{0}}$ =1.

and as $\frac{V_{ob}}{V_{sound}}$ → 1

⇒ $\frac{f}{f_{0}}$ → 2