Same chapter2 marksDifficulty: Medium
Why does a transformer not work on a direct-current supply?
Electromagnetism
3 marksDifficulty: Medium
What is the function of the split-ring commutator in a d.c. motor?
Original Khojo Papers practice question — not from a past board paper.
Answer
The commutator reverses the direction of the current through the coil every half revolution, at the moment the coil passes the vertical position. This keeps the couple acting in the same sense, so the coil goes on turning in one direction instead of oscillating.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
In an a.c. generator slip rings are used instead, because there the alternating output is wanted.
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