Question

If a copper wire of length 0.9 m and cross section `1mm^(2)` is stretched by a load of 1 kg then the extension in the wire will be
`(Y_(c )=1.2xx10^(11)N//m^(2) and g=10m//s^(2))`
A. 0.013 mm
B. 0.075 mm
C. 0.11 mm
D. 0.13 mm

Answer 1

Correct Answer - B
`e=(FL)/(Ay)=(1xx10xx0.9)/(10^(-6)xx1.2xx10^(11))`
`=(3)/(4) xx 10^(-4) = 0.75 xx 10^(-4)m`
`=0.075 mm`.