The electric potential `V` at any point `(x,y,z)`, all in meters in space is given by `V= 4x^(2)` volt. The electric field at the point `(1,0,2)` in volt//meter is

Options

A. 8 along negative X - axis
B. 8 along positive X - axis
C. 16 along negative X - axis
D. 16 along positive X - axis

Answer

A

Explanation

`vecE=-[hati(deltaV)/(deltax)+hatj(deltaV)/(deltay)+hatk(deltaV)/(deltaz)]`
`vecE=-[hati(8x)]`
`vecE_("(1,0,2)")=-8hati`
So electric field is 8 along negative x-axis.