Young's modulus of a wire is 2 × 10 11 N m - 2 . If an external stretching force of 2 × 10 11 N is applied to a wire of length L , the final length of the wire is (cross-section = unity)

Step-by-step solution

Given, Young's modulus of wire = 2 × 10 11   Nm - 2 Y = stress strain = F A × L ∆ L ⇒ 1 = ∆ L L ⇒ 1 + 1 = ∆ L L + 1 ⇒ 2 = ∆ L + L L ⇒ ∆ L + L = 2 L