Aquila Children's Magazine The Electric Issue | Page 9

MAKE THE DISC
THE SCIENCE BIT
9
With a pencil, draw a circle
approximately the same size as the
copper coil on a piece of paper and cut
it out.
Motors convert electrical energy (in
this case, from the battery), to
mechanical energy, which is used to
cause rotation.
10
With a sharp point, pierce a small
hole at the top and bottom, and
trim the sides so they fit between the
knots in the coil.
11
12
13
14
When a wire carrying current is
placed in a space with a magnetic
field, the wire experiences a force.
The size of the force depends on
three things:
 The amount of current in the wire
 The length of the wire
 The strength of the magnetic field
Draw a bird on one side.
Draw an upside down birdcage on
the other side of the circle.
Colour the disc in whichever way
you prefer.
Direction
of current
Cut two shorter lengths of
copper wire and use them
to connect the disc to
the rotor.
Coil is wound
clockwise
N
S
Magnetic field
(North pole up)
Front view
The direction of the force depends
on two things:
 The direction of the current
 The direction of the magnetic field
CONNECT IT UP
15
Slot the ends of the
copper wire through
the loops in your paper
clips. The coil should
spin freely.
16
Pick up your magnet,
hold it in front of the
coil. Give the coil a little
spin to get it moving.
N
S
Force
Force
N
S
Magnetic field
(North pole up)
Side view
When the rotor is given a spin, the
uninsulated (stripped) sections of
the wire come into contact with the
current. The circuit is complete and
current flows through the rotor.
When the rotor spins, the paper clip
comes into contact with the
insulated bit of the wire, causing
the circuit to be broken. Now current
is not flowing, instead the inertia
from the initial movement carries
the coil the rest of the way so the
uninsulated bit of wire reconnects
the circuit and the process begins
again. The coil spins, turning the
image over and over again, and your
eyes do the rest. AMAZING!
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