Question

A string is taken, its length is 40% and tension is increased ratio of the final and initial frequencies is

• A. 1 : 2
• B. 2 : 1
• C. 3 : 4
• D. 4 : 3

Answer 1

Answer: (B)

2 : 1

Fundamental frequency is given by
$n=\frac{1}{2I}\sqrt{\frac{T}{m}}$
$\Rightarrow \frac{n_1}{n_2}=\sqrt{\frac{T_1}{T_2}}\times \frac{I_2}{I_1}$
Given, $T_2=T_1+0.44T_1=\frac{144}{100}{T}_1$
$I_2=I_1-0.4I_1=\frac{3}{5}{I}_1$
$\Rightarrow \frac{n_2}{n_1}=\frac{2}{1}$