Wave Mechanics Question 850

Question: Find the frequency of minimum distance between compression & rarefaction of a wire. If the length of the wire is 1m & velocity of sound in air is 360 m/s

[CPMT 2003]

Options:

A) 90 sec?1

B) 180s?1

C) 120 sec?1

D) 360 sec?1

Show Answer

Answer:

Correct Answer: A

Solution:

The minimum distance between compression and rarefaction of the wire $ l=\frac{\lambda }{4} $

$ \

Therefore $ Wave length $ \lambda =4l $ Now by $ v=n\lambda \Rightarrow n=\frac{360}{4\times 1}=90 $

$ {{\sec }^{-1}}. $