A student changes a motor coil from 20 turns to 30 turns and reduces its current from 0.60 A to 0.40 A. The field, coil dimensions and coil position are unchanged. Each turn contributes the same turning effect for a given current. What happens to the total turning effect?
It stays the same because the product of turns and current is unchanged.
It increases because the number of turns alone determines the turning effect.
It decreases because the current alone determines the turning effect.
It doubles because both changes increase the force on each turn.
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.