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4.8 – ELECTROMAGNETISM
Y11 Physics
Scheme of Work (2005)
Lesson
1+
Learning Outcomes
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
State that like
magnetic poles
repel & unlike poles
attract.
Recall that iron &
steel can be
attracted by
magnets.
State that a force is
exerted on current
carrying wires in
magnetic fields.
Content
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2–3
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Recall that a force is
exerted on current
carrying wires in
magnetic fields, and the
application of this effect
in simple electric
motors.
Appreciate that electric
motors are found in a
variety of everyday
applications.
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Starter - Revise basic properties of magnets
(attraction of unlike poles, Fields, etc) from Y8.
Use handout sheet to produce a set of revision
notes & save time. Ask students to evaluate each
other’s work (peer assessment).
Discuss how magnets produce movement & ask
students for different examples (objects
containing motors, loudspeakers, etc).
DEMO: Force on a current carrying conductor
in a magnetic field (e.g., Al foil). Show that a
larger current will produce bigger force and
reversing current will reverse direction of
movement. Use the Building Blocks software to
illustrate Motor Effect. Students make
notes/diagram (Fleming’s LHR).
Plenary - Examples of motor effect using LHR
(diagrams on board).
Starter – Short quiz on LHR & simple board
problems, to recap work form last lesson. Ensure
that everyone understands key ideas.
VIDEO: Electricity & Magnetism (Use the
Science Bank Revision clips to show Motor effect
& check students understand how it turns).
Discuss electric motors (look at diagram in book).
Explain briefly function of main parts and link to
the motor effect & LHR. Use Building Blocks to
demonstrate how a motor works. Students make
notes & label a diagram of a simple dc motor.
EXPT: Students build & test a simple dc
electric motor. If you are short of time then just
demonstrate a prepared one. Explain again the
function of each part.
Plenary – Students (in pairs) explain to each other
how a motor works. Give an exact answer and
ask them to mark their responses for accuracy
and use of technical language & key terms.
References
Co.Ord Phys 3:
p 156-163
Physics for
GCSE:
p 107-110
p 178
p 180-183
Could use KS4
No Messing
Powerpoints
Co.Ord Phys 3:
p 163
p 164-165
p 166-167
Physics for
GCSE:
p 111-114
Could use KS4
No Messing
Powerpoints
Homework ideas
Co.Ord Phys 3:
p 156 Q1 - Q4
p 159 Q1 + Q2
p 163 Q1 + Q2
This could be done as
an ICT experiment
using the Focus on
Fields software.
Risks
Should be C3
You could use
Boardworks KS4
Uses of
Electromagnetism
slides 8 - 10
Questions sheet.
Co.Ord Phys 3:
p 163 Q3
p165 Q1 – Q3
p 167 (blue box
exercise)
List devices that use
motors for different
types of movement.
June 2004 terminal
exam Q2e
Should be C3
Students should
keep any voltages
below 6V to avoid
overheating wires.
Lesson
4
Learning Outcomes



Recall that domestic
electricity is generated
by burning fuel in a
power station.
State that a voltage is
induced when a
conductor cuts
magnetic field lines or
when the magnetic field
changes.
Describe how simple
AC generators work.
Content
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
5–6
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Explain how
transformers work and
recall & use Ns/Np=
Vs/Vp .
Know that a voltage is
induced when the
magnetic field through
a coil changes.
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Starter - Discuss generators & revise basic principle
of thermal power stations by asking students to sketch
a simple flow chart (Heat water-Steam-Turbinesgenerators-Electricity). Ask students how the
generator works to turn KE into Electricity.
EXPT/DEMO: Students use a magnet, coil of wire
& galvanometer to induce a current. (Voltage is
induced when conductor cuts magnetic field lines of
magnetic field changes = Electromagnetic Induction).
Students make notes on the key facts about EM
induction (fact page). June 2002 terminal exam Q2
Ask what factors would affect the size/direction of the
induced voltage.
Revise AC, DC and Mains electricity (DEMO with
oscilloscope). Use example of students running a
marathon (1 line of 26 miles = DC or backwards &
forwards in the lab = AC. Same energy changed/work
done in either case). Distinguish between AC + DC
generators.
Plenary – Use past paper questions & sample
responses to discuss ‘perfect answers’ to questions
on induction.
Starter – Ask students about common devices that
use different voltages at home (make a list).
Discuss basic idea of Transformers (required to
change voltages along the National Grid) using some
common examples such as mobile phone rechargers.
DEMO: Show pupils how to build and use a simple
transformer using 2 c-cores. Outline procedure for
experiment and safety.
EXPT: Students investigate the effect of turns
ratio (Ns/Np) for the output voltage of a
transformer (change secondary coil).
Write up experiment – Use ICT (laptops) to tabulate
results and plot graph of Ns and Vs. Discuss class
results. Mention Step Up/Step Down transformer.
Define transformer formula (or some other variation of
this): Ns/Np= Vs/Vp
Try some sample questions on the whiteboard (you
could use Boardworks for this).
Plenary – Summary & quick quiz questions on
transformers.
References
Co.Ord Phys 3:
p 168-171
p 174-177
Physics for
GCSE:
p 117-118
Homework ideas
Co.Ord Phys 3:
p 169 Q1 + Q2
p 171 Q1 – Q3
p 177 (Blue box
exercise)
p 178 Q4, Q6, Q7
Risks
Should be C3.
You could use
Boardworks KS4
Uses of
Electromagnetism
slides 11 - 18
Could use KS4
No Messing
Powerpoints
(Electricity)
Students describe
places where
secondary generators
are essential (e.g.,
hospitals).
Building Blocks
can be used to
illustate the
process of
induction using
animations.
Extension/G+T:
Research other types
of power station used
in different countries
and environmental
laws or concerns
Co.Ord Phys 3:
p 172 - 173
Worksheets available
Should be C3.
Co.Ord Phys 3:
p 173 Q1 + Q2
p 178 Q2
Make sure that
Vin~2V and that Ns
is between 56 and
40, if Np is about 20
turns.
Physics for
GCSE:
p 119-120
Could use KS4
No Messing
Powerpoints
(Electricity)
You can do this as an
ICT experiment or
demo, using Class
Experiments software
(good as a quick
starter or plenary
activity)
Lesson
7
Learning Outcomes


Explain how
transformers work and
recall & use Ns/Np=
Vs/Vp .
Know that a voltage is
induced when the
magnetic field through
a coil changes.
Content



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
8
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Recall that for a given
power transmission,
high V reduces current
& energy losses.
Describe how electricity
is generated &
transmitted using the
National Grid.
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9
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TEST
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Starter – Revise last lesson with a True or False quiz.
Define transformer formula (or some other variation of
this): Ns/Np= Vs/Vp
Discuss theory of how transformers work (AC in
primary – creates a changing magnetic field in primary
and iron core – this induces a voltage in secondary
coil, which is also AC).
DEMO: Building Blocks animation of transformers
& how they work.
Students make their own notes (possibly a
sequencing exercise).
Calculations/questions on transformers.
Plenary – Give pairs of students 1 minute to explain
what they know about Transformers to each other.
Discuss need for transmitting electricity at high V and
low I (reduces energy losses due to heating effects).
Discuss energy losses & National Grid. You could
highlight some of the energy loss mechanisms that
occur.
DEMO: Building Blocks animation of transformers
as part of the National Grid.
Mention that most power stations are < 40% efficient
and waste energy as heat, causing environmental
concerns. We need to use our supplies of fossil fuels
wisely as they are non-renewable.
Exercise – Students produce a ‘fact page’ about the
National Grid & how/why transformers are used.
Plenary – Generating Electricity game (ICT activity –
see GHU or look in shared area) & summary of the
topic.
END OF UNIT TEST – Electromagnetism
Review answers & summarise topic
References
Co.Ord Phys 3:
p 172 – 173
Physics for
GCSE:
p 121-122
Homework ideas
Risks
Worksheets available
None
Co.Ord Phys 3:
p 173 Q1 + Q2
You could use
Boardworks KS4
Uses of
Electromagnetism
slides 19 - 26
Co.Ord Phys 3:
P 63 Q3
P 65 Q2
P 67 Q1 – Q4
p 175 Q2
p 178 Q5
None.
Could use KS4
No Messing
Powerpoints
(Electricity)
Co.Ord Phys 3:
p 174 – 175
p 62 - 67
Physics for
GCSE:
p 117-118
Could use KS4
No Messing
Powerpoints
(Electricity)
Extension/G+T:
Describe how demand
for electricity will vary
throughout the day
and between
Summer/Winter.
The discussion of
power stations,
efficiency and
global warming
addresses issues of
Citizenship, and
could stimulate
further discussion
or work.
Review notes & revise
for test
None
None
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