A source of sound of frequency 256 Hz is moving rapidly towards a wall with a velocity of 5m/s. The speed of sound is 330

Q: A source of sound of frequency $256 Hz$ is moving rapidly towards a wall with a velocity of $5m/s$. The speed of sound is $330 m/s.$ If the observer is between the wall and the source, then beats per second heard will be .... $Hz$

a (a) The observer will hear two sound, one directly from source and other from reflected image of sound Hence number of beats heard per second =$\left( {\frac{v}{{v - {v_S}}}} \right)\,n - \left( {\frac{v}{{v + {v_S}}}} \right)\,n$ = $\frac{{2nv{v_S}}}{{{v^2} - v_S^2}} = \frac{{2 \times 256 \times 330 \times 5}}{{335 \times 325}} = 7.8 Hz$

SECTION - A [PHYSICS - MCQ]

GSEB - English Medium

A source of sound of frequency $256 Hz$ is moving rapidly towards a wall with a velocity of $5m/s$. The speed of sound is $330 m/s.$ If the observer is between the wall and the source, then beats per second heard will be .... $Hz$

A$7.8$
B$7.7$
C$3.9$
D$0$

Diffcult

STD 11 Science
NEET
STD 11 - 14. waves and sound
Physics

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