understand and explain experiments that demonstrate: • that a changing magnetic flux can induce an e.m.f. in a circuit • that the induced e.m.f. is in such a direction as to oppose the change producing it • the factors affecting the magnitude of the induced e.m.f.

understand the use of a Hall probe to measure magnetic flux density

define magnetic flux density as the force acting per unit current per unit length on a wire placed at right-angles to the magnetic field