Three rings, each having equal radius R, are placed mutually perpendicular to each other and each having its centre at the origin of co-ordinate system. If current I is flowing through each ring then the magnitude of the magnetic field at the common centre is

Question

G1 Physics · Accepted Answer

Each ring gives field B₀=μ₀I/(2R) at the common centre, along three mutually perpendicular axes. Hence B=√(B₀²+B₀²+B₀²)=√3·μ₀I/(2R). Therefore A.