Physicshard · Past Paper
What happens to the magnetic field at the center of a circular coil if its radius is doubled (keeping current and turns same)?
ADoubles
BRemains same
CHalved
DBecomes four times
✓ Correct Answer: C — Halved
The magnetic field at the center of a circular coil is inversely proportional to its radius (B ∝ 1/r).
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