Use Fleming's LH Rule to confirm that: AB : experiences force into page CD : experiences force out of page BC & AD:  parallel to field thus no force.

Use Fleming's LH Rule to confirm that: CD : experiences force into page AB : experiences force out of page BC & AD:  parallel to field thus no force.

To keep the coil rotating, the current must be reversed each time the coil has rotated through 180^°

The commutator does this. You should be able to use diagrams and/or other appropriate information to explain how electromagnetic effects are used in simple d.c. motors and circuit breakers.

NB Details of the split ring commutator, for reversing the current to a d.c. motor each half turn, has not been examined at GCSE (from 1993 onwards!)

Here is a link to a set of pages from Schoolscience - this takes you through how the motor works with some interactive illustrations - worth a look! (but remember the commutator is NOT on the syllabus anymore!)

Here is a link to a pdf that compares the motor and the generator - they are often confused by students because the scientific diagram is so similar!