What is angle between the electric field at a point and the equipotential surface passing through the point ?

The angle between the electric lines of force and an equipotential surface is

Show that the direction of electric field at a given is normal to the equipotential surface passing through that point.

What is angle between electric field and equipotential surface?

What is angle between electric field and equipotential surface?

Why is the electric field always at right angles to the equipotential surface ? Explain.

Two charges 2muC and -2muC are placed at points A and B is 6 cm apart:- What is the direction of the electric field at every point on the equipotential surface between them?