A uniform steel wire of length 3.14 m and diameter `2xx10^(-3)` m is fixed at its upper end. When a mass of 10 kg is attached to its lower end, the extension of the wire is `1xx10^(-3)` m. The Young's modulus of elasticity is,

Options

A. `9.8xx10^(8)N//m^(2)`
B. `9.8xx10^(9)N//m^(2)`
C. `9.8xx10^(10)N//m^(2)`
D. `9.8xx10^(11)N//m^(2)`

Answer

C

Explanation

`y=(FL)/(Ae)=(10xx9.8xx3.14)/(pi xx10^(-6) xx 10^(-3))=9.8xx10^(10)m`.