Question

A brass wire of length 5 m and cross section area `10^(-6) m^(2)` hung from rigid support with brass weight of volume `10^(-3)m^(3)` hanging from other end. Then the decrease in length of the wire when brass weight is completely immersed in water is,
`(g=10m//s^(2), Y_("brass")=10^(11)N//m^(2), rho_(w)=10^(3)kg//m^(3))`
A. `5xx10^(-4)m`
B. `3xx10^(-4)m`
C. `4xx10^(-4)m`
D. `2xx10^(-2)m`

Answer 1

Correct Answer - A
`l_(1)-l_(2)=(F_(1)-F_(2))(L)/(Ay)=(v rho gL)/(AY)`