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