A student observes that a copper wire moves sideways when current flows between the poles of a magnet. The wire moves the opposite way when only the current is reversed. Which explanation accounts for both observations?
The copper becomes a permanent magnet; reversing the current removes its magnetic poles.
The current produces a magnetic field; reversing the current reverses the field interaction force.
The copper is attracted by either pole; reversing the current reverses the magnet’s field.
The current increases the wire’s weight; reversing the current reverses the gravitational force.
86 exam-style questions on Edexcel GCSE Physics 12.3 The motor effect, covering 12.3.1 The motor effect, 12.3.2 Fleming's left-hand rule, 12.3.3 Force on a conductor, and 12.3.4 Electric motors. Each one has a worked solution and a mark scheme showing where the marks go.