## In This post you will get answer of Q.

Two wires A and B having lengths 7m and 5m respectively and $frac{y_A}{y_B} = frac{5}{7}$ . Both wires elongate by the same length under same load. If $r_A = 2mm, r_B$ is equal to {similar values}

Solution:

## $frac{I_{A}}{y_{A}A_{A}} = frac{I_{B}}{y_{B}A_{B}} $

$ frac{7}{y_{A}pi r^{2}_{A}} =frac{5}{y_{B} pi r^{2}_{B}} $

$ frac{r_{B}}{r_{A}} = sqrt{frac{5}{7} timesfrac{5}{7}} Rightarrow r_{B} = frac{5}{7}r_{A} $