wave_mechanics Beats Question 13
Question: A tuning fork and a sonometer wire were sounded together and produce 4 beats per second. When the length of sonometer wire is 95 cm or 100 cm, the frequency of the tuning fork is
[MP PMT 1990]
Options:
A) 156 Hz
B) 152 Hz
C) 148 Hz
D) 160 Hz
Show Answer
Answer:
Correct Answer: A
Solution:
Probable frequencies of tuning fork be $ n+4 $ or $ n-4 $ Frequency of sonometer wire $ n\propto \frac{1}{l} $
$ \therefore $
$ \frac{n+4}{n-4}=\frac{100}{95} $ or $ 95(n+4)=100(n-4) $ or $ 95n+380=100n-400 $ or $ 5n=780 $ or $ n=156 $
BETA
