Question

The electric potential V at any point O (x, y, z all in metres) in space is given by V = 4x² volt. The electric field at the point (1 m, 0, 2 m) in volt/metre is
(a) 8 along negative x-axis
(b) 8 along positive x-axis
(c) 16 along negative x-axis
(d) 16 along positive z-axis

Answer 1

Answer:

E = -dV/dx = -(8x)

Now this implies that potential is completely in x direction.

So we take the x coordinate, i.e, 1m

E= -8*1 = 8 along negative x axis