Question

There is some change in length when 33KN tensile force is applied on a steel rod of area of cross section 10^-3 m^2. The change of temperature required to produce the same elongation of the steel rod when heated is (Y = 3x10^11N/m^2, a =1.1x10^-5/°C)
(a) 10°C
(b) 20°C
(c) 30°C
(d) 40°C ​

Answer 1

Answer.

The correct option is C 10∘C

Modulus of elasticity =ForceArea×lΔl ....(1)

Given, Tensile force (F)=33,000 N

Area of cross-secton (A)=10−3 m2

Modulus of elasticity Y=3×1011N/m2

and

Coefficient of linear expansion of steel is α=1.1×10−5/∘C

Using the given data in (1), we get

3×1011=33,00010−3×lΔl