The electric potential decreases unifromly from 120 V to 80 V as one moves on the x-axis from x=-1 cm to x=+1 cm. The electric field at the origin

Options

A. must be equal to `20 V cm^-1`
B. must be equal to `20 Vm^-1`
C. may be greater than `20 Vm^-1`
D. may be less than `20 V cm^-1`

Answer

c

Explanation

`E_x = (d V)/(d x) = (120 - 80)/(2) = 20 Vm^-1`
There may be the y - and z - components of field also.