Simple Electric Circuits
 To know how to set up simple electric circuits, and represent these
using symbols and explain the energy transfers taking place
Energy & Money
 There are many ways a house can be
made more energy efficient, however
some of these techniques are more
cost-effective than others
 Complete the saving energy and money
worksheet
Energy & Money
 Payback time – eventually the money saved per year on reduced
heating bills will equal the initial cost of the insulation
Insulation Type
Cost
Saving Made In 1
Year
Payback Time
Double Glazing
£3000
£150
20 Years
Loft Insulation
£400
£200
2 Years
Cavity Wall
Insulation
£1000
£100
10 Years
Draught Excluders
£50
£10
5 Years
Hot Water Tank
Blankets
£25
£10
2.5 Years
Energy

There are 10 types of energy: 









Light energy - from the sun; a light bulb etc…
Sound energy - from a loudspeaker; a drum etc…
Kinetic (movement) energy - anything which moves!
Nuclear energy - transferred during a nuclear reaction
Thermal (heat) energy - transferred from hot objects to colder ones
Radiant heat (infra red) energy - transferred as electromagnetic
radiation by hot objects
Gravitational potential energy - possessed by anything with the
ability to fall
Elastic potential energy - stretched springs; elastic and rubber bands
etc…
Chemical energy - possessed by food; fuels; batteries etc
Electrical energy - a current in a circuit etc…
Electricity
 Energy can never be created or destroyed, it can only ever be
converted from one form to another
 Energy is only useful when it is converted from one form to
another
 Electricity is so useful because it can be easily transferred…
Electricity
 Electricity is the flow of electrical power (charge) in the form of
electrons
 Electricity is a useful secondary energy source – most energy
sources (like coal, oil, nuclear, wind etc…) can be converted into
electricity
Circuits
 A bulb in the circuit is like a radiator – an electrical device uses electrical
energy, supplied by the circuit
 The wires are like pipes - they
carry the flow of electricity
(current) around the circuit
Cell
+
Wires
 The electrical current is pushed
by the cell (battery) – this is the
voltage
 The electrons flow from –ve to
+ve
Lamp
Electrical Circuits
 An electric current needs two things:  Something to make the electricity flow (battery or power pack)
 A complete circuit
 Without these two basic things, an electric current will not flow
Cell
+
Wires forming a
complete circuit
-
Component Diagrams
 Circuit symbols are used to show the components in an electrical
circuit (wires are represented by straight lines)
Symbols
 Complete the simple electric symbols worksheet
Symbols
Task – to set up simple circuits
 Draw the circuit diagram in your book
 Explain what energy transfers are taking place
e.g. bulb energy transfer:
electrical heat & light (if there is a bulb in your circuit))
Cell
+
Wires
Switch
Lamp
Quiz