Electricity Generation

1
Electricity Generation
with Magnets or Lemons
2
If you want to do something useful - you need
energy

• We feel tired when we run out of energy
• So we eat to give us energy.

3
Our energy comes from food.

• When we eat
• we can walk, think, run, lift, turn, push, pull,
  and ------
• We need energy to work and play.

4
Energy makes things work
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What do we need to make these work?
Electricity!
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Without electricity - -

• We might use
• Candles
• Coal fires
• Semaphore to send messages
• Piano
• - - -

Without electricity our lives would be very
different.
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What is electricity?

• It is the movement of very, very tiny particles
  called electrons.
• As the tiny, tiny particles move they carry
  energy
• Electricity flows through wires
• -

8
Switch
Supply of electricity
Light bulb
Electrons
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How big are electrons?

• How many electrons in a piece of copper wire 1mm
  thick and 10cm long?

100,000,000,000,000,000,000 One hundred million
million million or one hundred billion billion
Electrons are very, very small
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Electricity transports energy from one place to
another

• For this we need
• A complete circuit made of conductors with lots
  of electrons
• Something to provide energy to push the
  electrons round the circuit
• To where we want to use it.

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Why is electricity important?

• It can make things work.
• It is easy to move the energy around using wires
• to just where you want it!

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How is electricity made?

• We need something to provide energy to push
  the electrons around the circuit.
• 2 main choices

A battery
or
A generator
13
Lemon battery
14
A battery
- uses chemistry to release energy

• Portable
• Cheap

• only store a fixed amount of energy
• big, heavy batteries are needed to store lots
  of energy

In a car a large battery is used to start the
engine and light the lamps.
15
Generators

• Use energy to make electricity
• A moving magnet is able to push the electrons
  along a wire.
• The energy to move the magnet is carried by the
  electricity,

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Magnet
Light bulb
Electrons
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Magnet
Magnet has to move to make electricity
Light bulb
Electrons
18
We can generate electricity
- by moving a powerful magnet through a coil of
wire.
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What have we learned?

• Energy makes things work.
• Electricity can carry energy to where we need it.
• Electricity can be made using
• a battery
• a generator.

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Huge generators as big as houses are needed to
generate electricity for homes, factories and
schools.

• We can generate electricity -
• but only small amounts
• - even when we work hard.