If the stress on a wire is 107NM-2 and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The young’s modulus of the wire is
-
A.
5 . 0 x 104 Nm-2 -
B.
5 . 0 x 105 Nm-2 -
C.
2 . 0 x 108 Nm-2 -
D.
2 . 0 x 109 Nm-2
Correct Answer: Option D
Explanation
Y = stress/strain, but stress = 107Nm-2 (given).
Strain = e/l0. = (10.05 – 10.00)/10.00 = 0.005
Thus Y = 107/0.005 = 2 . 0 x 109Nm-2