Question

A segment of wire vibrates with a fundamental frequency of $450Hz$ under a tension of $9kg$ weight. Then tension at which the fundamental frequency of the same wire becomes $900Hz$ is

• A. $36kg-wt$
• B. $27kg-wt$
• C. $18kg-wt$
• D. $72kg-wt$

Answer 1

Answer: (A)

$36kg-wt$

frequency $f\propto \sqrt{T}$
$\therefore \frac{f_1}{f_2}=\sqrt{\frac{T_1}{T_2}}$
$\frac{1}{2}=\sqrt{\frac{9}{T_2}}$
$T_2=4\times 9=36$