The potential for a point charge +q placed at a distance d from a grounded infinite conducting plate is V(x, y, z)=k q ( 1 x^2+y^2+(z-d)^2 - 1 x^2+y^2+(z+d)^2 ) Here k=1 / 4 ₀ is a constant. The maximum value of induced charge density on the conducting plate is