The potential V is varying with x as `V = (1)/(2) (y^2 - 4 x)` volt. The field at `x = 1m, y = 1 m,` is.

Options

A. `2 hat i + hat j Vm^-1`
B. `- 2 hat i + hat j Vm^-1`
C. `2 hat i - hat j Vm^-1`
D. `-2 hat i + 2 hat j Vm^-1`

Answer

C

Explanation

`E_x = - (d V)/(d x) = -(1)/(2) [-4] = 2`
`E_y = (d V)/(d y) = -(1)/(2) [2 y] = -y = -1`
`:. vec E = E_x hat i E_y hat j`.