The specific resistance and area of cross section of the potentiometer wire are `rho'` and `A` respectively. If a current `i` passes through the wire, its potential gradient will be

Options

A. `A//Irho`
B. `IrholA`
C. `I rho //A`
D. `I rho//l A`

Answer

C

Explanation

Potential gradient is given by,
`=Irho`
`=I.(R)/(l)` but `rho=(RA)/(l) :.(R)/(l)=(rho)/(A)`
`=Ixx( rho)/(A)`