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Force, Energy & Communication
Lesson 9
Bits and Bobs lesson
Lesson Objectives
Appreciate the factors affecting the speed of an electric motor
To understand the different ways of carrying a current
To be able to define voltage.
The electric motor
The important parts of an electric motor are:
A coil of wire which becomes an ____________ when current passes through it.
The electric motor
Two permanent magnets with opposite poles facing, to make a strong _______ ______ .
The electric motor
Two brushes that touch onto the _________ of the coil.
How the motor worksArrange these sentences into the correct order.
How the motor works
The force on this side is downwards This pair of forces makes the motor spin round. This is how the forces of the coil make the motor
turn. On the other side of the coil, the current is passing
the other way, from back to front. The force on this side is upwards. On one side of the coil, the current is passing from
front to back.
Arrange these sentences into the correct order.
How the motor works
This is how the forces of the coil make the motor turn.
How the motor works
This is how the forces of the coil make the motor turn.
On one side of the coil, the current is passing from front to back.
How the motor works
This is how the forces of the coil make the motor turn.
On one side of the coil, the current is passing from front to back.
The force on this side is upwards.
How the motor works
This is how the forces of the coil make the motor turn.
On one side of the coil, the current is passing from front to back.
The force on this side is upwards. On the other side of the coil, the current is
passing the other way, from back to front.
How the motor works
This is how the forces of the coil make the motor turn.
On one side of the coil, the current is passing from front to back.
The force on this side is upwards. On the other side of the coil, the current is
passing the other way, from back to front. The force on this side is downwards
How the motor works This is how the forces of the coil make the
motor turn. On one side of the coil, the current is passing
from front to back. The force on this side is upwards. On the other side of the coil, the current is
passing the other way, from back to front. The force on this side is downwards This pair of forces makes the motor spin
round.
Electric current
In a wire the current is caused by a flow of negative electrons.
However – not all current is carried by electrons!
Come round the front bench!
Electrolysis of copper sulphate!
Electric current
In an ionic liquid the current can be carried by the charged ions.
In copper sulphate the positively charged Cu ions carry the charge the negative electrode.
The negatively charged sulphate ions carry the charge to the positive electrode.
Electrolysis is the exception to the rule that current is carried
by the negatively charged electrons!
Defining the volt! This is HIGHER paper only!
Voltage is a measure of how much ENERGY each unit of charge has.
Defining the volt! This is HIGHER paper only!
Energy is measured in JOULES.
Defining the volt! This is HIGHER paper only!
Energy is measured in JOULES.
Charge is measured in COULOMBS
Defining the volt! This is HIGHER paper only!
Energy is measured in JOULES.
Charge is measured in COULOMBS
So 1 volt = 1 joule per coulomb!
Lesson Objectives
Appreciate the factors affecting the speed of an electric motor
To understand the different ways of carrying a current
To be able to define voltage.
