Choose the correct statements about the electrostatics of conductors.
A. Inside a charged conductor, the electrostatic field is zero.
B. The electrostatic field at the surface of a charged conductor must be tangential to the surface at any point.
C. There is no net charge at any point inside the conductor.
D. Electrostatic potential is constant throughout the volume of the conductor.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A, C and D only
In electrostatic equilibrium the free charges of a conductor rearrange themselves until they no longer move, and this fixes how the field, charge and potential behave.
(A) Inside a charged conductor, the electrostatic field is zero. — Correct. A field inside would keep pushing the free electrons, so in equilibrium the field inside is zero.
(B) The electrostatic field at the surface of a charged conductor must be tangential to the surface at any point. — Incorrect. A tangential component would move the surface charges; in equilibrium the field is normal to the surface.
(C) There is no net charge at any point inside the conductor. — Correct. By Gauss’s law, a closed surface drawn anywhere inside the material has \( E = 0 \) on it, so it encloses no net charge; any excess charge resides on the surface.
(D) Electrostatic potential is constant throughout the volume of the conductor. — Correct. With \( E = 0 \) inside, no work is done in moving a test charge within the conductor, so the whole volume is at one potential.
NCERT (2026-27):
Electrostatics of Conductors – “… Electrostatic field is zero inside a conductor.”
Electrostatics of Conductors – “… Thus electrostatic field at the surface of a charged conductor must be normal to the surface at every point.”
Electrostatics of Conductors – “… This means there is no net charge at any point inside the conductor, and any excess charge must reside at the surface.”
Electrostatics of Conductors – “… That is, there is no potential difference between any two points inside or on the surface of the conductor.”