A load of 20N on a wire of cross-sectional area 8 x 10-7m2, produces an extension of 10m2. calculate Young’s modulus for the material of the wire if its length is 3m
-
A.
7.0 x 1011Nm-2 -
B.
7.5 x 1011Nm-2 -
C.
8.5 x 1011Nm-2 -
D.
9.0 x 1011Nm-2
Correct Answer: Option B
Explanation
Young’s modulus = (frac{F}{A}) (div) (frac{e}{L})
= (frac{20}{8 times 10^{-7}}) (div) (frac{10^{-4}}{3})
= 7.5 x 1011Nm-2