AP EAMCET Engineering 2018 Apr 24 Shift 1 Paper

The expression of longitudinal strain is given by,
ε=

F

YA

Δl

l

=

F

YA

Substitute values,

Δl

l

=

22

1.1×1011×10−6

Δl

l

=2×10−4
The expression of the Poisson’s ratio is,
µ=Δd∕dΔl∕l
Substitute values,
0.32=

Δd∕d

2×10−4

Δd

d

=6.4×10−5
So, the change in radius is,

Δr

r

=6.4×10−5
The fractional change in area is,

ΔA

A

=2

Δr

r

ΔA

0.01

=2(6.4×10−5)
ΔA=1.28×10−6cm2