A table tennis ball which has been covered with conducting paint is suspended by a silk thread so that it hangs between two plates, out of which one is earthed and the other is connected to a high voltage generator. This ball:
Correct answer: C. Swings backward and forward hitting each plate in turn
- A. Is attracted towards high voltage plate and stays there
- B. Hangs without moving
- C. Swings backward and forward hitting each plate in turn
- D. Is attracted to earthed plate and stays there
Explanation
The neutral ball is first attracted to the high voltage plate via induction. Upon touching it, the ball acquires the same charge and is repelled towards the earthed plate. It then transfers its charge and is attracted back, creating a continuous shuttle effect.
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