In a tensile test on a metal bar of diametrer 0.015 m and length 0.2 m, the relation between the load and elongation within the proportional limit is found to be `F=97.2xx10^(6)(DeltaL),` where F is the load (in N ) and `(Delta L)` is the elongation (in m).
The Young's modulus of the material in Gpa is

Options

A. 75.5
B. 85.6
C. 98.7
D. 110

Answer

D

Explanation

Given that, diameter of metal bar (d) = 0.015 m
length (L) = 0.2 m
`F = 97.2 xx 10^(6) xx delta L`
We know that, Y `=(FL)/(A.DeltaL)`
`rArr Y = (97.2xx10^(6)xx0.2xx4)/(3.14 xx (0.015)^(2))`
`=110063.69 xx10^(6)=110 ` Gpa