Question:
Two circular coils of radii $5.0 \mathrm{~cm}$ and $10 \mathrm{~cm}$ carry equal currents of $2.0 \mathrm{~A}$. The coils have 50 and 100 turns respectively and are placed in such a way that their planes as well as the centers coincide. Find the magnitude of the magnetic field B at the common center of the coils if the currents in the coils are
(a) in the same sense.
(b) in the opposite sense.
Solution:
