Download P2 Topic 2 - Downham Market Academy

P2: Physics for your future
Page 1 of 4
Lesson P2.4 Current and voltage
Specification learning
outcomes
2.1 Describe how an
ammeter is placed in series
with a component to
measure the current, in
amps, in the component
2.2 Explain how current is
conserved at a junction
2.3 Explain how the current
in a circuit depends on the
potential difference of the
source
2.4 Describe how a
voltmeter is placed in
parallel with a component
to measure the potential
difference (voltage), in
volts, across it
[H] 2.5 Demonstrate an
understanding that
potential difference
(voltage) is the energy
transferred per unit charge
passed and hence that the
volt is a joule per coulomb
HSW statements
Prior learning
from KS 3
HSW 3 many
phenomena can be
explained by
developing and using
scientific theories,
models and ideas
Year 8 Explain,
using data and a
simple model, the
differences between
series and parallel
circuits
HSW 11 presenting
information, developing
an argument and
drawing a conclusion,
and using scientific,
technical and
mathematical
language, conventions
and symbols and ICT
tools
Year 9 Investigate
current and voltage
in circuits and draw
conclusions from a
range of data
Exemplar teaching activities
Starter: Yo! Sushi
Explain to students how the Yo! Sushi restaurants work (a
conveyor belt winds through the restaurant and diners take
dishes from it as they pass, then pay at the end depending
on how many and which kinds of dishes they have eaten).
Ask students to compare how the restaurants work to an
electric circuit, listing similarities and differences.
Main: Conservation of current demonstration
Demonstrate that current is conserved at a junction using
demonstration ammeters. This could also be done as a class
practical if time and resources allow. See the Teacher and
technician practical sheet P2.4 (2) for full details.
Plenary: Spot the mistakes
Ask students to work in small groups to draw three circuit
diagrams, each of which contains at least one mistake.
These can include things such as the readings on different
ammeters in a circuit or a voltmeter placed in a circuit to
measure the potential difference. Groups swap drawings and
try to identify the mistakes. Check selected samples to
make sure that there are no misconceptions being
reinforced.
Homework: Worksheets P2.4c (for students requiring extra
support) and P2.4d (for those working at a higher level)
contain questions on Current and circuits.
Main
differentiation
Resource
sheets
Stretch: Ask
students to predict
what will happen to
the current readings
if a third bulb is
added to the same
branch.
Teacher
and
technician
practical
sheet P2.4
(2)
Support: Students
could act out a
circuit, with each
student being a unit
of charge. All go
through a 'cell', but
then split up to
follow two separate
paths. They should
be able to see that
the number going
through the 'cell'
must be the same as
the total going
through the two
branches.
Worksheet
P2.4c
Worksheet
P2.4d
BTEC
Links
P2: Physics for your future
Page 2 of 4
Lesson P2.5 Investigating voltage, current and resistance (Practical)
Specification
learning outcomes
2.6 Investigate the
relationship between
potential difference
(voltage), current and
resistance
HSW statements
HSW 1 the collection and
analysis of scientific data
HSW 2 the interpretation
of data, using creative
thought, to provide
evidence for testing ideas
and developing theories
HSW 3 many phenomena
can be explained by
developing and using
scientific theories, models
and ideas
HSW 5 planning to test a
scientific idea, answer a
scientific question or solve
a scientific problem
HSW 6 collecting data
from primary or secondary
sources, including the use
of ICT sources and tools
HSW 7 working accurately
and safely, individually
and with others, when
collecting first-hand data
HSW 8 evaluating methods
of data collection and
considering their validity
and reliability as evidence
HSW 10 using both
qualitative and
quantitative approaches
HSW 11 presenting
information, developing
an argument and drawing
a conclusion, and using
scientific, technical and
mathematical language,
conventions and symbols
and ICT tools
Prior learning
from KS 3
N/A
Exemplar teaching activities
Starter: Blowing bulbs
Use a low voltage bulb in a circuit where the voltage
produces too high a current for it, and show students
that the bulb 'blows'. Set up the circuit again with a
new bulb, but this time with a resistor in the circuit as
well. Show students that the bulb survives this time,
and ask them to suggest why this is.
Main:
Students follow the instructions on Worksheet P2.5b.
This prompts students to take current and voltage
readings at several different power pack voltage
settings for each of 5 resistors. The range of data that
students need to collect is given on Worksheet P2.5c
which students will also need. This sheet guides
students through recording, considering their results,
and evaluating their investigation.
You could ask students to come up with one or two
further hypotheses, based on their observations in this
practical.
Main
differentiation
N/A
Resource sheets
Teacher and
technician practical
sheet
Worksheet P2.5b
Worksheet P2.5c
BTEC
Links
P2: Physics for your future
Page 3 of 4
Lesson P2.6 Changing resistances
Specification learning
outcomes
2.7 Explain how changing the
resistance in a circuit changes
the current and how this can be
achieved using a variable
resistor
2.8 Use the equation: potential
difference (volt, V) = current
(ampere, A)  resistance (ohm,
Ω), V = I  R
2.9 Demonstrate an
understanding of how current
varies with potential difference
for the following devices:
a) filament lamps b) diodes c)
fixed resistors
2.10 Demonstrate an
understanding of how the
resistance of a light-dependent
resistor (LDR) changes with light
intensity
2.11 Demonstrate an
understanding of how the
resistance of a thermistor
changes with change of
temperature (negative
temperature coefficient
thermistors only)
HSW statements
HSW 3 many
phenomena can be
explained by
developing and using
scientific theories,
models and ideas
HSW 11 presenting
information, developing
an argument and
drawing a conclusion,
and using scientific,
technical and
mathematical
language, conventions
and symbols and ICT
tools
HSW 10 using both
qualitative and
quantitative
approaches
Prior learning
from KS 3
Year 9
Investigate
current and
voltage in
circuits and
draw
conclusions
from a range of
data
Exemplar teaching activities
Starter: Design a circuit
Ask students to design an automatic control circuit for car
lights that go on when it gets dark or a thermistor that
changes with temperature (or any other simple task they
may come up with themselves). Keep students' ideas and
revisit later in the lesson so they can amend their ideas if
necessary.
Main: Varying the potential difference practical
Students obtain data and draw current–voltage graphs for
fixed resistors, filament lamps and diodes. Students need
not test fixed resistors if they have done the practical work
in lesson P2.5. See Worksheet P2.6a and the Teacher and
technician practical sheet P2.6 (2) for full details.
Plenary: Components and graphs
Worksheet P2.6c provides a set of cards showing the
different components looked at in this lesson, their circuit
symbols and graphs showing their characteristics. Ask
students to match up the cards and label the axes on the
graphs.
Homework: Worksheet P2.6e is designed for students
working at a higher level and provides questions about the
components studied in this lesson. Students will also need a
sheet of graph paper.
Main
differentiation
Resource
sheets
Stretch: Do not give
students the part of
the worksheet
showing them how
to tabulate and
present their
results, so they can
work out for
themselves the best
way of displaying
the data.
Worksheet
P2.6a
Support: Help
students to draw a
table for their
results and help
them to work out
the resistances for
each set of current
and voltage
readings. They may
also need help
plotting the negative
currents and
voltages on a graph.
Worksheet
P2.6e
Teacher
and
technician
practical
sheet P2.6
(2)
Worksheet
P2.6c
BTEC
Links
P2: Physics for your future
Page 4 of 4
Lesson P2.7 Transferring energy
Specification learning
outcomes
2.12 Explain why, when
there is an electric current
in a resistor, there is an
energy transfer that heats
the resistor
[H] 2.13 Explain the energy
transfer (in 2.12 above) as
the result of collisions
between electrons and the
ions in the lattice
2.14 Distinguish between
the advantages and
disadvantages of the
heating effect of an electric
current
2.15 Use the equation:
electrical power (watt, W)
= current (ampere, A) 
potential difference (volt,
V), P = I  V
2.16 Use the equation:
energy transferred (joule,
J) = current (ampere, A) 
potential difference (volt,
V)  time (second, s), E = I
Vt
HSW statements
Prior learning
from KS 3
Exemplar teaching activities
HSW 3 many
phenomena can be
explained by
developing and using
scientific theories,
models and ideas
Year 7 Use a model
to describe the flow
of current and begin
to recognise some of
its strengths and
weaknesses
Starter: Heating wire wool demonstration
HSW 11 presenting
information, developing
an argument and
drawing a conclusion,
and using scientific,
technical and
mathematical
language, conventions
and symbols and ICT
tools
Year 8 Explore
different models to
explain the flow of
current and the
transfer of energy
Students have already met the equation for calculating
power from current and potential difference, in P1 Topic 5.
Lesson P1.29 included a practical to measure the power of
various low voltage devices. This could be repeated here.
Year 9 Evaluate
different models
used to explain the
flow of current and
the transfer of
energy
Write some typical power ratings on the board (e.g. electric
drill 1500 W) and ask students to work in pairs to create
three power or energy calculation questions each using this
data. They should also write mark schemes for their
answers. They then swap questions with their partners and
work out the answers. Higher tier students should be
encouraged to include questions that involve changing the
subject of the equation.
HSW 10 using both
qualitative and
quantitative
approaches
HSW 12 the use of
contemporary science
and technological
developments and their
benefits, drawbacks
and risks
Demonstrate the heating effect of a current using wire wool.
See the Teacher and technician practical sheet P2.7 for full
details.
Main: Calculating power
Plenary: Power questions
Homework: Worksheets P2.7b (for students requiring extra
support) and P2.7c (for those working at a higher level)
contain questions on Heating and power.
Main
differentiation
Resource
sheets
Stretch: Ask
students to explain
why the heating
effect of a current
increases with a
higher current.
Teacher
and
technician
practical
sheet P2.7
Support: Work
through the
examples step by
step on the board,
asking students to
tell you where
various numbers
should go.
Worksheet
P2.7b
Worksheet
P2.7c
BTEC
Links