Another important learning outcome under subtopic 3.2 is to describe:
How a direct current motor works??..this such question can come out in SPM essay paper2

- to describe this, 1st u need to know how the diagram of dc motor looks like.
- then u need to label it, such as which one is the commutator, carbon brush and other component.

Description:

• A direct current (DC) motor which consists of a coil of many turns uses the magnetic turning effect.

• The current flows into the coil through a pair of carbon brushes. The carbon brushes push against commutator.

• then, the commutator changes contact from one brush to another while the coil is turning. This is to keep the coil rotating continuously.

The next thing u need to know is the factors that affect the speed of rotation. The speed of rotation can be increased by:

• increasing Amount of Current
• increasing the strength of magnetic field
• increasing No. of coils

basically, if u understand the whole concept, u can build your own electric motors..watch these videos..