Question

In Melde's experiment, $8$ loops are formed with a tension of a $0.75N.$ If the tension is increased to four times then the number of loops produced will be -

• A. $4$
• B. $8$
• C. $2$
• D. $12$

Answer 1

Answer: (A)

Melde's experiment is used to analyse the standing waves.
In this experiment, $T{p}^2=\text{Constant}$ , where $T$ is tension in string and $p$ is number of loops in the string.
$\Rightarrow T_1{p}_1^2=T_2{p}_2^2\Rightarrow p_2^2=\frac{T_1{p}_1^2}{T_2}$
As tension is increased to four times, $p_2^2=\frac{T_1{p}_1^2}{4T_1}=\frac{p_1^2}{4}=\frac{8^2}{4}=16$
$\Rightarrow p_2=4$