Question

A steel wire of lm long and cross section area is hang from rigid end. When weight of 1kg is hung from it then change in length will be (given

• A. 0.5 mm
• B. 0.25 mm
• C. 0.05 mm
• D. 5 mm

Answer 1

Answer: (C)

0.05 mm

Answer 2

$l = \frac { M g L } { Y A } = \frac { 1 \times 10 \times 1 } { 2 \times 10 ^ { 11 } \times 10 ^ { - 6 } } = 0.05 \mathrm {~mm}$