Electromagnet is like a ‘temporary magnet’. When a current flows through the solenoid, it will be magnetised. When the current is switched off, the eletromagnet loses its magnetism.
To make the electromagnet stronger,
1) Increase the number of turns in the solenoid.
2) Increase the size of the current.
3) Insert a soft iron core in the solenoid.
– iron is a soft magnetic material
– it can be magnetised easily
– it can be demagnetised easily
This is a very simple DC (direct current) motor, which may not turn continuous nor it is stable.
For it to turn continuous, it needs a split ring commutator. (not shown here)