90. A steel wire of lm long and cross section area is
A steel wire of lm long and cross section area is 1mm2 hang from rigid end. When weight of 1kg is hung from it then change in length will be (given Y=2×1011N/m2)
(a) 0.5 mm (b) 0.25 mm
(c) 0.05 mm (d) 5 mm
Answer-c
(3)