There is same change in length when a 33000 N tensile force is applied on a steel rod of area of cross-section `10^(-3)m^(2)` . The change of temperature reuired to produce the same elongation, if the steel rod is heated , if (The modulus of elasticitay is ` 3xx10^(11) N//m^(2)` and the coefficient of linear expansion of steel is ` 11 xx 10^(-5) //^(@)C`).

Options

A. `20^(@)`C
B. `15^(@)C`
C. `10^(@)C`
D. `0^(@)C`

Answer

C

Explanation

(c) Modulus of elasticity `=("Froce")/("Area")xx(l)/(Deltal)`
`3xx10^(11)=(3000)/(10^(-3))xx(l)/(Deltal)`
`(Deltal)/(l)=(33000)/(10^(-3))xx(1)/(3xx10^(11))=11xx10^(-5)`
Change in length, `(Deltal)/(l)=alpha DeltaT`
`11xx10^(-5)=1.1xx10^(-5)xxDeltaT`
`implies DeltaT=10K` or `10^(@)C`