Class 12 NEET Physics Electrostatics Questions Part 2

Concept:Electrostatic properties of charged conductors in static equilibrium.Formula:$E = \frac{\sigma}{\varepsilon_0}$ (at the surface, field normal to surface).Solution:• Statement A: Correct. Inside a conductor, the electrostatic field is zero.• Statement B: Incorrect. Electric field at the surface is $E = \frac{\sigma}{\varepsilon_0} \hat{n}$, which depends on surface charge density $\sigma$.• Statement C: Correct. In static situation, excess charge resides only on the surface, not in the interior.• Statement D: Correct. At the surface, the electrostatic field is always perpendicular (normal) to the surface.• Statement E: Incorrect. Electrostatic potential is constant throughout the conductor, but it can be non-zero.Shortcut:Use the known fact: For a conductor in electrostatics, field inside is zero, field at surface is normal and depends on $\sigma$, excess charge is on surface, and potential is constant (not necessarily zero).Answer:Option C (A, C and D only).