Question

To increase the frequency by $20\%$, the tension in the string vibrating on a Sonometer has to be increased by

• A. $44\%$
• B. $33\%$
• C. $22\%$
• D. $11\%$

Answer 1

The correct option is A $44\%$

frequency increased by $20\%$$\Rightarrow f^{{}^{\prime }}=\frac{6}{5}f$
$\therefore \sqrt{T^{{}^{\prime }}}=\frac{6}{5}\sqrt{T}$
$\sqrt{T^{{}^{\prime }}}=\sqrt{\frac{144}{100}}T$
$\therefore$ Tension is to be increased by $44\%$