Question

Two waves $y=0.25\text{ }sin\,316t$ and $y=0.25\,\sin 310\,t$ are travelling in same direction. The number of beats produced per second will be :

• A. 3
• B. 6
• C. $3\pi$
• D. $3/\pi$

Answer 1

Answer: (D)

$3/\pi$

Answer 2

Comparing the given equations with the standard equation of wave. We have ${{n}_{1}}=\frac{316}{2\pi }$ and ${{n}_{2}}=\frac{310}{2\pi }$ hence number of beats is $=\frac{316}{2\pi }-\frac{310}{2\pi }=\frac{6}{2\pi }=\frac{3}{\pi }$