A circular coil produces a magnetic field at its centre
PHYSICS · Single correct · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A circular coil produces a magnetic field B at its centre. If its radius is doubled while the current remains unchanged, how will the magnetic field at the centre change?
(a) It becomes one–fourth as large.
(b) It remains unchanged.
(c) It becomes half as large.
(d) It becomes 21 times as large.