The force required to stretch a wire of cross-section 1 cm 2 to double its length will be : (Given Yong's modulus of the wire = 2 × 10 11 N m - 2 )

Step-by-step solution

The wire is stretched to double its length. Therefore, if the length of the wore was l , change in the length ∆ l = l . Applying Hooke's law, Y = stress strain = F l A ∆ l ⇒ F = Y A ∆ l l = Y A ⇒ F = 2 × 10 11 × 1 × 10 - 4 = 2 × 10 7   N = 2 × 10 11 × 10 - 4 2 l - l l = 2 × 10 7   N