Q.
Beats are produced by two waves given by $y_{1} = a\sin{2000\pi t\ and\ y_{2}a\sin{2008\pi t}}$. The number of beats heard per second is
A) Zero
B) One
C) Four
D) Eight
Explanation
(c) Number of beats per second= $n_{1}\sim\ n_{2}$
$\omega_{1} = 200\pi = 2\pi v_{1}$
$\Longrightarrow n_{1} = 1000\ $
And $\omega_{2} = 2008\pi = 2\pi n_{2}$
$\Longrightarrow n_{2} = 1004$
Number of beats heard per second
=1004-1000=4
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.