At one point on the surface of a charged metal body, the electric field just outside the surface makes an angle of \(60^\circ\) with the surface. This shows that
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → the free charges on the surface are still moving, so the static situation has not been reached
In the static situation, the field at the surface of a charged conductor is normal to the surface. A field at \(60^\circ\) to the surface has a part along the surface. That part pushes the free charges on the surface.
Option (1) the surface charge density at that point is different from that at other points — Incorrect. The surface charge density of a conductor can vary from point to point. Even then, in the static situation the field is normal at every point. So a slanted field does not come from a change in charge density.
Option (2) the charges on the surface of this body are held in fixed positions — Incorrect. A metal has free electrons. The charges on its surface can move along the surface, so they are not fixed.
Option (3) the free charges on the surface are still moving, so the static situation has not been reached — Correct. The part of the field along the surface exerts a force on the free surface charges. So they move, and charges are still flowing. The field becomes normal only when this flow stops.
Option (4) the body has some excess charge inside its volume — Incorrect. The direction of the field at the surface tells us nothing about charge inside. In the static situation, any excess charge stays on the surface.
NCERT (2026-27):
Electrostatics of Conductors – “If E were not normal to the surface, it would have some non-zero component along the surface. Free charges on the surface of the conductor would then experience force and move. In the static situation, therefore, E should have no tangential component.”