Question

Frequency of a sonometer wire is n. Now its tension is increased 4 times and its length is doubled then new frequency will be

• A. n/2
• B. 4n
• C. 2n
• D. n

Answer 1

Answer: (D)

n

Answer 2

$n \propto \frac{1}{l}\sqrt{T}$⇒ $\frac{n^{'}}{n} = \sqrt{\frac{T^{'}}{T}} \times \frac{l}{l^{'}} = \sqrt{4} \times \frac{1}{2} = 1$⇒ $n^{'} = n$