Question

The dimensions of four wires of the same material are given below. In which wire the increase in length will be maximum when the same tension is applied

• A. Length 100 cm, diameter 1 mm
• B. Length 200 cm, diameter 2 mm
• C. Length 300 cm, diameter 3 mm
• D. Length 50 cm, diameter 0.5 mm

Answer 1

The correct option is D Length 50 cm, diameter 0.5 mm

If same force is applied on four wires of same material then elongation in each wire depends on the length and diameter of the wire and given by $l\propto \frac{L}{d^2}$ and the ratio of $\frac{L}{d^2}$ is maximun for (d) option.