If M=mass of wire, `rho`=density of wire, R=radius of wire, r=change in radius, L=original length of wire and l=change in length, then poisson's ratio is given by

Options

A. `(Mr rho)/(pi R^(3)l)`
B. `(Mr)/(pi R^(2)l rho)`
C. `(Mr)/(pi R^(3) rho l)`
D. `(Mr rho)/(pi r^(2)l)`

Answer

C

Explanation

`sigma =((r )/(R ))/((l)/(L))=(rL)/(Rl) " "`…(i)
`M=rho v =rho pi R^(2)L`
`therefore L=(M)/(rho pi R^(2))`
Substitute L in equation no. (i),
`sigma=(rM)/(rho pi R^(2)Rl)`
`sigma=(rM)/(rho pi R^(3)l)`