Question

The Young's modulus of a wire of length L and radius r is Y. If the length is reduced to L/2 and the radius to r/2, its Young modulus will be
a. Y/2
b. 2Y
c. Y
d. 4Y

Answer 1

The equation for Young's Modulus is tensile stress/tensile strain.

Stress = \[F/A _{0}\]
Strain = \[DeltaL/L _{0}\]
Area = \[\pi r ^{2}\]
If you put these equations together and plug in the before and after conditions you will find your answer :)

Answer 2

Seems like Y. Is it?