The adjacent graph shows the extension `Deltal` of a wire of length 1m, suspended from the f top of a roof at one end and with a loaf w connected to the other end. If the cross-sectional area of the wire is `10^(6) m^(2)` calculate the young's modulus of the material of the wire .

Options

A. `2xx10^(11) N//m^(2)`
B. `2xx10^(-11) N//m^(2)`
C. `3xx10^(-12) N//m^(2)`
D. `2 xx 10^(-13) N//m^(2)`

Answer

A

Explanation

(a) We have, `(DeltaL)/(W)=((4-1)xx10^(-4))/(80-20)=(10^(-4))/(20)`
Elongation , `DeltaL=(WL)/(AY)impliesY=(L)/(A)(W)/(DeltaL)`
Young's Modulus , `Y=(1)/(10^(-6))xx(20)/(10^(-4))=2xx10^(11) Nm^(-2)`