PHYSICS · Subjective · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism
Problem
Two coaxial circular coils, P and Q, each of radius 12 cm, are placed concentrically in the same plane. Coil P has 50 turns and carries a current of 4 A, while coil Q has 80 turns and carries a current of 3 A.
(i) Derive an expression for the net magnetic field at their common centre when the currents in both coils flow in the same direction.
(ii) Using the expression obtained, calculate the magnitude of the net magnetic field at the centre for the given values.
(iii) If the current in coil Q is reversed while that in coil P remains unchanged, determine the new net magnetic field at the centre.