Two wires each of radius 0 . 2   cm and negligible mass, one made of steel and the other made of brass are loaded as shown in the figure. The elongation of the steel wire is ______ 10 – 6   m . [Young's modulus for steel = 2 × 10 11   N   m – 2 and g = 10   m   s – 2 ]

Step-by-step solution

The force acting on steel wire F is 2 + 1 . 14   g = 3 . 14 g From the relation of Young's modulus, it can be written F A = Y Δ L L ⇒ Δ L = F L A Y = 3 . 14 × g × 1 . 6 π × 0 . 2 2 × 2 × 10 11 × 10 - 4 ⇒ ∆ L = 2 × 10 - 5 ⇒ ∆ L = 20 × 10 - 6   m