At a recycling centre, a mixture of steel cans and aluminium cans moves along a conveyor belt.
A large electromagnet with an iron core is held above the belt. When the electromagnet is switched on, the steel cans are lifted off the belt. When it is switched off, the steel cans drop into a container.
Explain why the steel cans are lifted off the belt but the aluminium cans are not.
Explain why the core of the electromagnet is made of iron rather than steel.
A worker suggests replacing the electromagnet with a large permanent magnet made of cobalt steel.
Evaluate this suggestion.
70 exam-style questions on Edexcel GCSE Physics 12.1 Magnets and magnetic fields, covering 12.1.1 Magnetic poles, 12.1.2 Magnetic materials; permanent and induced magnets, 12.1.3 Magnetic fields, and 12.1.4 Plotting compasses and the Earth's magnetic field. Each one has a worked solution and a mark scheme showing where the marks go.