Question

In Melde’s experiment, when the tension in the string is 10 g wt then three loops are obtained. Determine the tension in the string required to obtain four loops, if all other conditions are constant.

Answer 1

Let us assume that the Fork is in perpendicular position for our convenience.

For this experiment , N = `P/(2l) xx sqrt(T/m)`

Here N is the frequency, p is the number of loops, $l$ is length, T is tension and m is linear density of string.

It is mentioned that all conditions except the tension are constant.

Hence N will be equal for both.

∴ `P_1/(2l) xx sqrt(T_1/m) = P_2/(2l) xx sqrt((T_2)/m)`

`P_1/P_2 = sqrt(T_2/T_1)`

∴ `T_2 = (P_1^2 xx T_1)/(P_2^2) = (3^2 xx 10)/4^2 = 5.625`

5.625 g wt