RADT 142 Week 9 Electromagnetism and Magnetism

Who is Alessandro Volta and what did he do?

An Italian physicist and chemist who invented the first electric battery called the Voltaic Pile

Who is Hans Christian Oersted and what did he do?

Danish physicist and chemist who discovered that electric currents create magnetic fields, showing that electricity and magnetism are connected

What is electromagnetic induction?

The production of an electric current from a changing magnetic field

Who is Michael Faraday and what did he do?

British scientist who discovered that current is induced by a moving magnetic field (electromagnetic induction)

What is Faraday's Law of Magnetism?

Describes how a changing magnetic field induces an electric current in a circuit

You can control the magnitude of the induced current by controlling the:

1. Strength of magnets

- Stronger magnet = Larger current

2. Speed of motion

- Moving the magnet or coil faster = Greater induced current

3. Direction of motion

- 90° to Magnetic Field = Most current (When the wire is perpendicular to the magnetic field, it has the most current)

4. Shape of the conduction

- More turns (loops) in the coil = Stronger current

What is the Right thumb rule?

When your hand is holding a current-charged wire, the current will run up the wire and the fingers wrapping around will show the direction of the magnetic field

Current flows North to South

What is a helix?

A coil of wire

What is a solenoid?

A coil of wire (helix) with a current

What is an electromagnet?

A solenoid with a ferromagnetic material (iron) as its core

A ferromagnetic material is a substance that can become strongly magnetized — it's attracted to magnets and can also become a magnet itself.

When ferromagnetic material is present, the magnetic strength is

increased

What is Lenz Law of Electromagnetism

The induced current flows in the opposite direction of the applied current

When current starts flowing through a coil (like in an electromagnet), it creates a magnetic field. If the current changes — increases or decreases — the magnetic field also changes. According to Lenz's Law, any change in magnetic flux through a circuit induces a current that opposes the change that produced it.

Results in back EMF or principle of self induction

What is Back EMF or the principle of self induction?

Back EMF is the induced voltage that opposes the applied voltage

The principle of self induction is the principle behind Back EMF.

Self-Induction is the induction of an opposing EMF in a single coil by its own changing magnetic field

What is mutual induction?

When a magnetic field induces a current in a nearby helix