Question

Two wires of same diameter of the same material having the length l and 2l. If the force F is applied on each, the ratio of the work done in the two wires will be

• A. 1 : 2
• B. 1 : 4
• C. 2 : 1
• D. 1 : 1

Answer 1

Answer: (A)

1 : 2

Answer 2

$W = \frac { 1 } { 2 } F l$ ∴ $W \propto l$ (F is constant)

∴ $\frac { W _ { 1 } } { W _ { 2 } } = \frac { l _ { 1 } } { l _ { 2 } } = \frac { l } { 2 l } = \frac { 1 } { 2 }$