A circular coil of turns and radius produces a magnetic field of magnitude at its…
PHYSICS · Single correct · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A circular coil of N turns and radius R produces a magnetic field of magnitude B at its centre when it carries a current I. The same piece of wire is rewound to form another circular coil of half the original radius while the current is kept the same. Assuming no loss of wire length, what is the magnitude of the magnetic field at the centre of the new coil?
(a) 8B
(b) 4B
(c) B
(d) 2B