Wave Mechanics Question 894
Question: 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
[CPMT 1990; DCE 1999]
Options:
A) Zero
B) One
C) Four
D) Eight
Show Answer
Answer:
Correct Answer: C
Solution:
Number of beats per second = $ n _{1}\tilde{\ }n _{2} $
$ {\omega _{1}}=2000\pi =2\pi n _{1} $
Therefore n1 = 1000 and $ {\omega _{2}}=2008\pi =2\pi n _{2} $
Therefore n2 = 1004 Number of beats heard per sec$ =1004-1000=4 $