Copper of fixed volume V is drawn into a wire of length l. When this wire is subjected to a constant force F, the extension produced in the wire is `Deltal`. Which of the following graphs is a straight line?

Options

A. `Deltal` versus `l^(2)`
B. `Deltal` versus `l`
C. `Deltal` versus `(1)/(l)`
D. `Deltal` versus `(1)/(l^2)`

Answer

A

Explanation

As `Y=(F//A)/(Deltal//l)`
`rArr" "Deltal=(Fl)/(AY)`
But `V=Al`, so `A=(V)/(l)`
`therefore" "Deltal=(Fl^2)/(VY).propl^(2)`
Hence graph of `Deltal` versus `l^(2)` will give a straight line.