Electrostatic Induction via Earthing

Steps:

• Positive rod repels electrons from sphere, inducing negative charge on near side and positive on far side.
• Earthing connects far side to ground, allowing electrons to flow in, neutralizing positive charge and leaving net negative charge on sphere.
• Removing earth connection traps the net negative charge on the insulated sphere.
• Removing rod allows negative charge to redistribute uniformly across the sphere.

Why C is correct:

• Diagram C shows a uniformly negative sphere, consistent with charging by induction where earthing with a positive inducer results in net opposite charge (Coulomb's law of attraction/repulsion).

Why the others are wrong:

• A shows neutral sphere, ignoring charge transfer from earthing.
• B shows positive sphere, reversing the induction effect of a positive rod.
• D shows charge separation, which dissipates after rod removal due to conductor equilibrium.

Final answer: C