The area of a cross-section of steel wire is 0.1 cm2 and Young's modulus of steel is 2×1011 N m-2. The force required to stretch by 0.1% of its length is

Here,  A = 0.1 cm2 = 0.1 × 10-4m2Y = 2× 1011 Nm-2∆LL = 0.1% = 0.1100 = 0.1 ×10-2As Y = FA∆LL              F = Y∆LLA  = 2 × 1011 Nm-2×0.1×10-7×0.1×10-4 m2 = 2 × 103 N = 2000 N