Wave Mechanics Question 723

Question: A 1 cm long string vibrates with fundamental frequency of 256 Hz. If the length is reduced to $ \frac{1}{4}cm $ keeping the tension unaltered, the new fundamental frequency will be

[BHU 1997]

Options:

A) 64

B) 256

C) 512

D) 1024

Show Answer

Answer:

Correct Answer: D

Solution:

$ n\propto \frac{1}{l} $

Therefore $ \frac{n _{2}}{n _{1}}=\frac{l _{1}}{l _{2}} $

Therefore $ n _{2}=\frac{l _{1}}{l _{2}}n _{1}=\frac{1\times 256}{1/4}=1024Hz $