A circular coil of 150 turns and radius is wound over a cylindrical core of magnetic…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
A circular coil of 150 turns and radius 7.5cm is wound over a cylindrical core of magnetic material whose relative permeability is μr=220. The coil carries a current of 0.80A. Assume that the magnetic material is magnetically linear and completely fills the interior of the coil.
(i) Calculate the magnitude of the magnetic field at the centre of the coil when the core is present.
(ii) By what factor does this field exceed the magnetic field at the centre of the same coil when the core is absent? Present your answer to one decimal place.