A source and an observer move away from each other with a velocit… - Vidyadip

MCQ

A source and an observer move away from each other with a velocity of $10\; m/s$ with respect to ground. If the observer finds the frequency of sound coming from the source as $1950 \;Hz$, then actual frequency of the source is .... $Hz$ (velocity of sound in air = $340\; m/s$)

A
$1903$
✓
$2068$
C
$2100$
D
$602$

✓

Answer

Correct option: B.

$2068$

b
$n' = n\,\left( {\frac{{v - {v_O}}}{{v + {v_S}}}} \right) = n\,\left( {\frac{{340 - 10}}{{340 + 10}}} \right) = 1950$

$ \Rightarrow $$n = 2068$$Hz$

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