Do now!
Can you continue with the
‘Draw the sentences’ from last lesson?
This is to be FINISHED
FOR HOMEWORK. Due next Friday 16th
September.

Today’s lesson
• Plotting magnetic fields
• Electromagnetic induction

Plotting magnetic fields

Can you gather around Mr
Porter?
Quietly and sensibly

Plotting magnetic fields

Magnetic field lines
The arrows show the direction a compass needle would point at that point in the field.
The closer the field lines are, the stronger the magnetic force felt

Field around a bar magnet

Electromagnetic induction
• Can you carefully wind your wire around the cardboard tube?

Electromagnetic induction
• Put your coil in this circuit. The multimeter should be on the μA scale.
μA

Electromagnetic induction
• MOVE a magnet in and out of the coil.
Watch the meter!
μA

Electromagnetic induction
If a magnet is moved inside a coil an electric current is induced
(produced)

Electromagnetic induction
If a magnet is moved inside a coil an electric current is induced
(produced)
COPY this please!

Electromagnetic induction
A electric current is induced because the magnetic field around the coil is changing
(the coil ‘cuts through’ the lines of field).
COPY this please!

Gather round

• http://phet.colorado.edu/sims/faraday/gene rator_en.jnlp

Can you stick this in please?
Generator/dynamo
A generator works by rotating a coil in a magnetic field (or rotating a magnet in a coil). A slip-ring commutator produces alternating current
(a.c.)

COPY this please!

Let’s try some questions!
Pages 215 and 219.