A sonometer wire stretched by a tension of `1.5kg` weigth, has the fundamental frequency of 256 Hz. How much addition weigth should be placed on the hanger. In order to produce its octave ?

Options

A. `1.5 kg wt`.
B. `3 kg wt`.
C. `4.5 kg wt`.
D. `6 kg wt`.

Answer

C

Explanation

`n propto sqrtT " and " n_(2) = 2n_(1)`
` :. ` T should be 4 times ` = 4 xx 1.5 = 6 ` kg. wt.
` :. ` Extra weight ` = 4.5` kg wt.