Transcript Do now! - MrSimonPorter

To make an electromagnet
stronger
The 3 C’s
• More Coils
• More Current
• Use an iron Core
Can you
copy this
please?
Last lesson
• Field around a wire
• Electromagnetism Investigation
Moving charges (currents)
Moving charges (electric currents) also
produce a magnetic field
Conventional current –
electrons flow in the
opposite direction
http://www.sciencebuddies.org
Magnetic field around a straight wire
You can use the right
hand screw rule to
decide which direction
the field goes
Stronger field closer to
wire
Magnetic field around a straight wire
You can use the right
hand screw rule to
decide which direction
the field goes
Stronger field closer to
wire
Can you
copy this?
“Making electromagnets
Investigation”
To make an electromagnet
stronger?
To make an electromagnet
stronger
The 3 C’s
• More Coils
• More Current
• Use an iron Core
Today’s lesson
• Field patterns around a wire, solenoid and
coil.
• The motor effect
• Making a loudspeaker
Field around a solenoid (coil)
Field around a coil
Can you gather
around Mr
Porter?
The Motor Effect
When a current is placed in a magnetic
field it will experience a force (provided the
current is not parallel to the field). This is
called the motor effect.
Can you
copy this
sentence
into your
books
please.
The Motor Effect
The direction of the force on a current in a
magnetic field is given by Flemming’s left
hand rule.
Thumb = Motion
First finger = Field direction
Centre finger = Conventional Current
The Motor Effect
Can you copy
this please?
WITH
DIAGRAM!
The direction of the force on a current in a
magnetic field is given by Flemming’s left
hand rule.
Thumb = Motion
First finger = Field direction
Centre finger = Conventional Current
Sample question
In this example, which way will the wire be
pushed? (red is north on the magnets)
Sample question
In this example, which way will the wire be
pushed? (red is north on the magnets)
Current
Field
Can you gather
around Mr
Porter?
Again?!
Building a loudspeaker
These also use the motor effect
Coil in here
magnet
Let’s read!
Pages 210 and 213. The answer
the questions on all pages. Finish
for homework due 15th October