Age 11-14
British Energy
Circuits
3
3
3
3
3
3
3
3
3
3
3
3
Notes for teachers
Contents
There are three chapters in this electronic resource, covering basic ideas about electric circuits and how
these can be used to solve simple electrical problems.
1
Basic circuits looks at simple series circuits: how the components are connected together,
the need for a complete conducting path, how a switch works, how cells provide the voltage
needed to push a current around the circuit, and how to measure electric current. It ends with
a discussion of energy transfer in an electric circuit.
2
Series and parallel considers these two ways of connecting components, and the meaning of
resistance. It looks at the conservation of current in both cases.
3
Circuit challenges provides a series of opportunities for building increasingly complex virtual
circuits, in response to questions. These can be tackled during the two preceding chapters,
or at the end.
1
www.schoolscience.co.uk/content/3/physics/circuits/index.html
Age 11-14
British Energy
Circuits
3
3
3
3
3
3
3
3
3
3
3
3
Notes for teachers
Curriculum links (using the COL keyword scheme)
Electricity and Magnetism
Circuits - generally
Series circuits
Parallel circuits
Components in circuits: batteries, etc.
Electric current
Voltage
Electrical resistance/conductivity
Mains electricity – generally
Web links
How copper conducts
www.schoolscience.co.uk/content/4/chemistry/copper/copch0pg3.html
2
www.schoolscience.co.uk/content/3/physics/circuits/index.html
Age 11-14
British Energy
Circuits
3
3
3
3
3
3
3
3
3
3
3
3
Notes for teachers
Using the resource
1 - An introduction to electric circuits
Relevant prior knowledge: Students should have experience of creating simple circuits and using them to
switch components on and off.
Start by showing picture 1.2. Point out that this is what
we call a series circuit, with the components connected
end-to-end.
Move your cursor over the blue text ‘light up’ and observe
the lamp light up as the switch closes. This shows the
functionality of the circuit. Now move your cursor over
the blue text ‘around’ to show the explanatory current
arrows. At all times, refer to the current flowing around a
circuit or through a component. (This will help students to
distinguish between current and voltage.) Relate this flow
to the series connection of the components.
Use picture 1.3 to show how a switch works, emphasising
the need for a complete circuit of metal.
On page 1b, use picture 1.4 to relate current flow to
the polarity of the cell or battery. Use question 2 to
emphasise the rules for connecting cells together.
Page 1c allows you to compare electric current to the
mechanism by which a bicycle chain transfers energy
from the rider to the back wheel. Show picture 1.6 and
move your cursor over the blue words in the text to
the right. You can now consider how current can be
measured using an ammeter, connected in series. Use
Circuit challenge 3 to show that current is the same at all
points around a circuit.
For most students, the surprising thing about electric current is that it does not get used up as it travels
around a circuit. This is only surprising to students who have not learned to distinguish between
current and energy; it is the energy that is transferred around a circuit which is ‘used up’ by the various
components, and which is transferred by means of the current. page 1d allows you to elucidate this. Use
question 4 to check understanding of energy transfers involving electricity.
3
www.schoolscience.co.uk/content/3/physics/circuits/index.html
Age 11-14
British Energy
Circuits
3
3
3
3
3
3
3
3
3
3
3
3
Notes for teachers
Using the resource
2 - Using the Circuit Challenges for teaching about electric circuits
Use a data projector to show these challenges in turn. They will allow you to build up your students’
understanding in a logical progression.
As you discuss each circuit, pose questions such as, “What do you think will happen when we close the
switch?”, “What will this ammeter show?” and “Can you explain why the lamps are dimmer?”
You could break up the presentation by asking students to construct real circuits themselves, either
before showing the virtual version (so that they can predict what will happen), or afterwards (to check that
the virtual one is correct).
The 10 challenges are as follows:
Challenge 1 Make a simple series circuit with a cell, a lamp and a switch; observe what happens when
you close the switch.
Challenge 2 Add cells to a battery and making the lamp brighter.
Challenge 3 Measure current in a simple series circuit, to show that it does not get used up.
Challenge 4 Change the number of cells in a battery to show that the current increases.
Challenge 5 Add lamps in series and show that the brightness decreases.
Challenge 6 Show that the current in a series circuit with two lamps is less than the current in a circuit
with a single lamp.
Challenge 7 Make a parallel circuit with a cell and two lamps. Observe the brightness of one of the
lamps when you disconnect the other one.
Challenge 8 Measure the current at various points in a parallel circuit.
Challenge 9 Build some challenging circuits.
Challenge 10 Build some more challenging circuits with 4 cells.
(The last two allow you to start with a blank circuit and develop your own ideas.)
Use Student worksheet 1, Circuit challenges, which includes questions relating to each of the ten
challenges.
2 - Other activities
Dismantle a torch to see the continuity of the metal parts. Examine the switch closely, and look at the
bulb, identifying how the current flows into the bulb, through the filament, and out again. Look at mains
light bulbs (bayonet and screw-fit) to see the same features of these.
Make practical circuits using standard laboratory equipment; attempt to mimic the circuits shown in the
electronic resource.
4
www.schoolscience.co.uk/content/3/physics/circuits/index.html
British Energy
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Circuits
Student worksheet 1
Age 14-16
Circuit Challenges
Challenge 1 In the space on the right, draw
a circuit diagram showing a series circuit with
a cell, a lamp and a switch, so that the lamp
comes on when you close the switch.
Challenge 2 Use the web activity to add cells to a battery and observe the effect this has on the
brightness of the lamp.
1. As the number of cells increases, the lamp becomes _____________.
2. If you have too many cells, the lamp may _____________.
Challenge 3 Measure current at different points around a simple series circuit.3.
Current is measured using an ___________ which is connected in _______ in the circuit.
4. The current is ______
_______ at all points around a series circuit.
number of cells
current
current
current
Challenge 4 What happens to the current if you change the number of cells in a battery? Put a
ring around the correct graph.
number of cells
number of cells
S1
www.schoolscience.co.uk/content/3/physics/circuits/index.html
British Energy
3
3
3
3
3
3
3
3
3
3
3
3
3
Circuits
Student worksheet 1
Age 14-16
brightness
brightness
brightness
Challenge 5 Use the web activity to connect two or more lamps (in series). Observe what
happens to the brightness when you connect more lamps in series. Put a ring around the correct
graph.
number of lamps
number of lamps
number of lamps
Challenge 6 Measure the current in a series circuit, firstly with one lamp, then with two lamps.
Fill in the results – don’t forget the units.
1 cell, 1 lamp: current =
1 cell, 2 lamps: current =
2 cells, 1 lamp: current =
2 cells, 2 lamps: current =
Challenge 7 Make a parallel circuit with a cell and two lamps. What do you observe happening.
Challenge 8 Measure the current at various points in a parallel circuit. In the space below, draw
a diagram of a parallel circuit and add arrows to show how the current flows around it.
S1
www.schoolscience.co.uk/content/3/physics/circuits/index.html