Transcript
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.
