5. Learning Objectives
• A – To use both Fleming’s left and right
hand rules
• M - to gain an understanding of how
current is induced in coil of wire using a
magnet
• S – to explain the difference between
an A.C. and D.C. generator
6. Inducing Current Direction
• Lenz’s Law – an induced current always
flows in the direction that oppose the
change which it produced
7.
8. Faraday’s Right hand rule
To find out the direction of induced
current from motion you must use
faraday’s right hand rule (not left)
13. Left hand or right?
Motion
To find out the
force from the
current its Left
hand
To find out the
current from
the motion its
Right hand
14. Eddy Currents
• Eddy currents can be used to slow down
a magnet with a non-magnetic metal
• A metal that is non-magnetic but
conducts a current will generate Eddy
Currents when it moves near a magnet.
• These currents oppose the motion of
the metal and cause it to slow down.
15. Video
Watch the video and answer
these questions
1. What type of current is used to levitate the plate?
2. What type of metal is the plate made from? Is it magnetic?
3. Do the two magnetic fields on faraday’s ring attract or repel each other?
4. How large is the current being passed through the wires?
5. What type of currents do you think are being generated in the metal
plate (think of the material the plate is made from)
6. What type of energy is a by-product these currents?
16. A.C. Generators
• Most of our
electricity comes
from electric
generators.
• Simply put it is a
coil of wire spun
inside a magnet
and an A.C current
is produced
