Two oppositely charged spheres A and B successively attract an uncharged conducting ball C placed near them; therefore, ball C must be______________?
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Answer: B. electrically neutral
Explanation
Electrostatic induction polarizes an uncharged conducting ball, creating temporary attraction toward both positive and negative charges. Oppositely charged spheres exert attractive forces on induced charges of opposite polarity within the neutral conductor. Net charge on the conducting ball remains zero despite experiencing attractive electrostatic forces from both sides. Electrostatic induction causes free electrons inside a conductor to redistribute when placed near an external electric field. Coulomb's law describes the electrostatic force existing between stationary electrically charged particles or objects in space. Conductors allow internal charge carriers to move freely, unlike insulators which restrict internal electron mobility completely.
A positively charged ball would experience repulsion from one of the oppositely charged source spheres instead of universal attraction. A negatively charged ball would similarly be repelled by the negatively charged source sphere in the experiment setup. Possessing both positive and negative net charges simultaneously is physically impossible for a single macroscopic conducting object.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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