A simple motor coil has just passed the position where its turning effect is zero. Its split-ring commutator fails to reverse the current. Which explains why the motor will not continue to be driven in the same direction?
The magnetic poles have exchanged positions, so the current in the coil becomes larger.
The magnetic poles have exchanged positions, so the current in the coil becomes zero.
The sides have exchanged positions, so unchanged forces now oppose the rotation.
The sides have exchanged positions, so unchanged forces now increase the rotation.
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.