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

Options

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

Answer

B

Explanation

Young.s modulus `Y = (Fl )/( A Delta l )`
`implies Delta l = (Fl )/( Ay)`
But ` V =Al,so A = (V)/(l)`
`therefore Delta l = (Fl ^(2))/( YV) prop l ^(2), F, Y, V` are same
`therefore` Graph will be `Delta l to l ^(2).`