Question

The electric potential at a point (x,y) in the x-y plane is given by v=-kxy . The field intensity at a distance r from origin varies as?

Answer 1

You know
V-Electric potential
r=distance
Electric field intensity,E=-dV/dr

Potential at orgin =-k*0*0=0
potential at distance r from orgin (r,r)=-k*r*r=-kr^2

dV=potential at distance r from orgin (r,r) - Potential at orgin
=-kr^2

=>E=-dV/dr=-2kr