The drawing shows two cylinders. They are identicle in all respects, except one is hollow. In a setup like that in figure identical forces are applied to the right end of each cylinder while the left end is fixed.

Options

A. The elongation of A is morethan that of B
B. The elongation of B is morethan that of A
C. The energy stored in B is more than is A
D. The energy stored in A is more than that in B

Answer

B, C

Explanation

`F/A=y(Deltal)/l RightarrowDeltal=((lF)/r)1/A`
`RightarrowU=1/2((Deltar)/l)Deltal^(2)=1/2(Deltar)/l((DeltaF)/r)^(2) 1/A^(2)`
`Rightarrow Upropto1/A`