An earthed conductor is placed near another positively charged conductor. The net charge acquired by the earthed conductor will be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Negative only
The positive conductor attracts electrons to the nearer side of the earthed conductor. Because the conductor is earthed, electrons flow in from the earth to take the place of the positive charge that would be repelled to the far side. The repelled positive charge is neutralised by this flow and passes into the earth.
The conductor is therefore left with an excess of electrons: its net charge is negative only.
Option (1) Positive only — Incorrect. Positive charge is driven to the far side and is neutralised through the earth connection.
Option (2) Negative only — Correct. Electrons flow in from the earth and stay on the conductor, held by the attraction of the positive conductor.
Option (3) Zero — Incorrect. The charge is induced, and the earth supplies the electrons, so it does not stay neutral.
Option (4) Both positive and negative on the far and near sides, respectively — Incorrect. The far-side positive charge flows to the earth because the conductor is earthed.