(a)[2]
State Faraday’s law for electromagnetic induction.
(b)[4]
A coil of insulated wire is wrapped around one end of a ferrous core and attached to a battery, as shown in Fig. 10.1. An aluminium ring sits on the core. The ring is able to move freely along the core’s length. The switch starts open. Use Faraday’s law and Lenz’s law to explain why the aluminium ring jumps upwards when the switch is closed.