A tension of 20 N is applied to a copper wire of cross sectional area 0.01 `cm^(2)`, Young's modulus of copper is `1.1 xx 10^11N//m^(2)` and Poisson's ratio is 0.32. The decrease in cross sectional area of the wire is

Options

A. `1.16xx10^-6cm^2`
B. `1.16xx 10^-5 m^2`
C. `1.16xx10^-4 m^2`
D. `1.16xx10^-3 cm^2`

Answer

A

Explanation

`l/(Deltal)=f/(AY)=20/(0.01xx10^(-4)xx1.1xx10^(11)=1.81xx10^(-4)`
`=1.162xx10^(-10) m^(2))=1.162xx10^(-6) cm^(2)`