PHYSICS · Multi-part · AP · Physics C: Electricity and Magnetism · Magnetic Fields and Electromagnetism · Magnetic Fields and Electromagnetism
Problem
Three identical coaxial circular loops, each of radius 8cm, are placed side by side so that the distance between the centres of successive loops is negligible compared with the radius. Each loop carries a current of 5A in the same direction.
(i) Determine the magnitude of the magnetic field at the common centre on the common axis due to the combination of the three loops.
(ii) State the direction of the resultant magnetic field at that point.
(iii) If the current in the middle loop alone is reversed while keeping the outer two unchanged, calculate the new magnitude of the resultant field at the centre and specify its direction.