Highly selective Backlog Qs for JEE MainPhysicsMechanical Properties of Solids
The area of cross-section of a railway track is 0 . 01 m 2 . The temperature variation is 10 ° C . Coefficient of linear expansion of material of track is 10 - 5 C - 1 ∘ . The energy stored per meter in the track is J m - 1 . (Young's modulus of material of track is 10 11 N m - 2 )
Correct answer
5
Step-by-step solution
Elastic energy = Y 2 ( strain ) 2 × Area × length ⇒ Elastic energy per unit length = Y 2 ( strain ) 2 × Area ( strain = Δ ℓ ℓ = α Δ T = 10 - 5 × 10 = 10 - 4 ) = 10 11 2 × 10 - 4 2 × 10 - 2 = 5 J m - 1