Basics in Magnetism Electromagnetism Force on a Current-Carrying Wire EM Induction Transformer Generators Electric Motors ELECTROMAGNETISM

What happens when you move a magnet into a coil of wire? Michael Faraday EM Induction Changing magnetic field can produce electricity!

How is a changing magnetic field produced? Using AC source Moving magnet in a coil of wire Moving wire in a magnetic field

What factors affect the emf produced? The number of loops The speed of the magnet The size of the coil of wire More turns, greater emf Faster, greater emf Greater size, greater emf

What factors affect the emf produced? The polarity of magnet Direction of motion Strength of Magnet Changes direction Greater strength, greater emf

The AC Generator Top view Allows contact with the rings while allowing them to slip past Prevents the wires from twisting

The AC Generator

The Transformer

Causes changing magnetic field Makes the field stronger Emf is induced in the coils

The Transformer V s > V p Step down transformer V s < V p Charging electronic gadgets Step up transformer Power transmission

Power Transmission There is less current at high voltage. Power loss is lower at high voltage.