Six original Cambridge-style questions on the d.c. motor: why the coil turns, the job of the split-ring commutator, making it faster, reversing it, and how it differs from a generator.
Explain why a current-carrying coil placed in a magnetic field begins to turn.
State the job of the split-ring commutator in a d.c. motor.
A student removes the commutator and connects the coil so the current cannot reverse. Describe what the coil does now, and explain why.
State three ways to increase the speed at which a d.c. motor turns.
State two separate changes, each of which on its own would reverse the direction in which the motor turns.
A d.c. motor uses a split-ring commutator, while an a.c. generator uses slip rings. State the different job each one does.
Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.