NTA Abhyas JEE Main2020PhysicsMechanical Properties of SolidsPractice
There is some change in length when a 33000 N tensile force is applied on a steel rod of the area of cross-section 10 - 3 m 2 . The change of temperature required to produce the same elongation, if the steel rod is heated, is (The modulus of elasticity is 3 × 10 11 N m - 2 and the coefficient of linear expansion of steel is 1 .1 × 10 - 5 ℃ - 1 )
Options
- A20   ° C
- B15   ° C
- C10   ° C
- D0   ° C
Correct answer
C. 10   ° C
Step-by-step solution
Modulus of elasticity = F o r c e A r e a × l ∆ l 3 × 10 11 = 33000 10 - 3 × l ∆ l ∆ l l = 33000 10 - 3 × 1 3 × 10 11 = 11 × 10 - 5 Change in length, ∆ l l = α ∆ T 11 × 10 - 5 = 1.1 × 10 - 5 × ∆ T ⇒ ∆ T = 10 K or 10 ° C