Electromagnetism

Electromagnetism

• Electromagnetism is a branch of physics that studies the interactions between electric currents and magnetic fields.
• Electromagnets are devices that produce magnetic fields only when electric current is flowing.

Electromagnetic Induction

• Electromagnetic induction is the process by which a changing magnetic field generates an electric current in a conductor.
• The principle of electromagnetic induction is used in transformers and generators.

Fleming’s Left Hand Rule

• Fleming’s left hand rule is used to predict the direction of motion in motors.
• Your thumb represents motion (Force), first finger the magnetic Field direction, and second finger the Current direction.

Transformers

• A transformer changes the voltage of an alternating current (AC) supply.
• They consist of two or more coils of insulated wire wound around a core made of iron.
• The coil connected to the incoming power supply is the primary coil, and the one connected to the outgoing circuit is the secondary coil.
• Step-up transformers increase voltage, while step-down transformers decrease voltage.

Electric Motors

• An electric motor converts electrical energy into mechanical energy.
• It operates on the principle of electromagnetic induction and uses Fleming’s left hand rule to determine direction of force.

The Generator Effect

• The generator effect is used to generate electricity.
• It works on the principle of electromagnetic induction where a change in magnetic field induces an electric current.
• Motor and generators are reverse of each other, in motors electrical energy is converted to mechanical energy, in generators it’s vice versa.

Remember these key concepts, as they form the basis of understanding electromagnetism. Good luck with your revision.