Download Electric Circuits

Y8 T4 – Electricity and Electrical circuits
02/05/2017
1.Simple Electrical Circuits
Objectives: To use circuit diagrams to describe what is needed for an
electrical circuit to work.
Starter: Describe how this torch works
Keywords:
Current
Electrons
Conductor
Insulator
Cell
Battery
Complete
circuit
Incomplete
circuit
Components
Include:
- What does the battery do?
- What is the switch for and how
does it work?
- When will the light switch on
and when does it switch off and
explain why this happens?
Y8 T4 – Electricity and Electrical circuits
02/05/2017
1.Simple Electrical Circuits
Objectives: To use circuit diagrams to describe what is needed for an
electrical circuit to work.
Learning outcomes
-Level 4: Identify situations when a circuit will be
on or off and connect the components in a circuit
diagram correctly.
-Level 5: Build circuits from circuit diagrams and
represent electrical circuits using circuit
diagrams.
-Level 6: Explain why an electrical circuit will only
work when a switch is closed and there is an
energy source
-Level 7: Use ideas about conductors and
insulators to explain why circuits do not work
when a switch is an open position.
Keywords:
Current
Electrons
Conductor
Insulator
Cell
Battery
Complete
circuit
Incomplete
circuit
Components
Y8 T4 – Electricity and Electrical circuits
02/05/2017
1.Simple Electrical Circuits
Objectives: To use circuit diagrams to describe what is needed for an
electrical circuit to work.
Keywords:
Current
Electrons
Conductor
Insulator
Cell
Battery
Complete
circuit
Incomplete
circuit
Components
Y8 T4 – Electricity and Electrical circuits
02/05/2017
1.Simple Electrical Circuits
Objectives: To use circuit diagrams to describe what is needed for an
electrical circuit to work.
You will attempt to
draw and make some
electrical circuits
using electrical
symbols. Follow the
instructions on the
worksheet to help
you.
When you have
finished you will
need to write a
paragraph explaining
what is needed to
make an electrical
circuit work.
A
This is an example of an
electrical circuit
diagram. What
components does it
contain?
Keywords:
Current
Electrons
Conductor
Insulator
Cell
Battery
Complete
circuit
Incomplete
circuit
Components
Y8 T4 – Electricity and Electrical circuits
1.Simple Electrical Circuits
Objectives: How do electrical circuits work?
02/05/2017
Keywords:
Series
Circuit
Charge flow
Components
Cell
Battery
Circuit
diagram
Y8 T4 – Electricity and Electrical circuits
2.Electric Current
Objectives: To describe and measure electrical current.
02/05/2017
Keywords:
Current
Starter: Draw Each of the circuit diagrams below in
Ammeter
your book. Label each of the components and suggest
which circuits will work and which won’t and explain why Resistance
Voltage
Amps
Components
Rubber
Y8 T4 – Electricity and Electrical circuits
2.Electric Current
Objectives: To describe and measure electrical current.
Learning outcomes
-Level 4: Describe what happens to the electrical
current when more components or more batteries
are added to a circuit.
-Level 5: Explain what is meant by the term
‘electrical current’ and describe how we can
measure it.
-Level 6: Use scientific ideas when explaining the
effects of adding batteries or bulbs to a simple
electrical circuit.
-Level 7: Use ideas about attraction and repulsion
of charges to explain why current flows.
02/05/2017
Keywords:
Current
Ammeter
Resistance
Voltage
Amps
Components
Exercise 7: Results
CONDUCTORS are materials that will allow electricity to pass
easily. INSULATORS do not allow electricity to pass easily.
1. Which materials from the investigation were conductors?
Copper, iron, graphite, lead, aluminium and nickel.
2. Which was the only conductor that was a non-metal?
Graphite.
3. Which materials from the investigation were insulators?
Wood, plastic, sulfur and glass.
4. What did you notice about all the insulators?
They were all non-metals.
5. Why is plastic used as the material for plug casings?
It is an insulator.
Exercise 8: Draw a Circuit
Diagram for the Apparatus Below
Exercise 9: Draw a Circuit
Diagram for the Apparatus Below
Exercise 10: Draw a Circuit
Diagram for the Apparatus Below
Exercise 11: Which is the Correct
Circuit Diagram for the Apparatus?
A.
B.

Exercise 12: Which is the Correct
Circuit Diagram for the Apparatus?
A.
B.

Y8 T4 – Electricity and Electrical circuits
2.Electric Current
Objectives: To describe and measure electrical current.
Current is a measure of the rate of flow of
electric charge in a circuit or how much
charge is passing a fixed point every second.
Current is measured in ampares (A) using an
ammeter.
The bigger the current the more charge is
passing a fixed point every second.
02/05/2017
Keywords:
Current
Ammeter
Resistance
Voltage
Amps
Components
Y8 T4 – Electricity and Electrical circuits
2.Electric Current
Objectives:
To describe and measure electrical current.
Copy and Complete:
02/05/2017
The ammeter is connected in the same loop/ in series. Keywords:
Current
It measures electric currents.
Ammeter
The voltmeter is connected in parallel.
Resistance
It measures potential differences.
Voltage
The more light bulbs we put in the circuit the light bulbs are
dimmer;
Amps
Potential difference are shared and is lower across each bulb;
Components
Current of the whole loop is lower.
Y8 T4 – Electricity and Electrical circuits
2.Electric Current
Objectives: To describe and measure electrical current.
Write a short story about a cat driving a chargedcar on a road of charges with all the keywords:
The cat in a charged car was driving on a road with
lots of charged particles. All the particles flows in
one direction and that’s called …………………
02/05/2017
Keywords:
Current
Ammeter
Resistance
Voltage
Amps
Components
Electron flow
Electricity in wires is a flow of electrons along the wire
from the negative end of the battery to the positive end
What do we call this flow of electrons? Electrical current
Y8 T4 – Electricity and Electrical circuits
02/05/2017
3.Energy and Current
Objectives: To be able to distinguish between current and energy in an
electrical circuit.
Learning outcomes
-Level 4: Identify the energy source in an
electrical circuit.
-Level 5: Describe what happens to the current
and energy in the circuit as electricity flows
through each component in the circuit.
-Level 6: Use a model to describe what happens to
the current and energy in a circuit as electricity
runs through it.
-Level 7: Apply ideas about current and energy to
different situations.
Keywords:
Voltage
Current
Electrons
Energy
transfer
Y8 T4 – Electricity and Electrical circuits
02/05/2017
3.Energy and Current
Objectives: To be able to distinguish between current and energy in an
electrical circuit.
Keywords:
Voltage
Current
Electrons
Energy
transfer
Link: Circuit analogy
animation
Y8 T4 – Electricity and Electrical circuits
02/05/2017
3.Energy and Current
Objectives: To be able to distinguish between current and energy in an
electrical circuit.
Where do the
flowing electrons
come from?
The delocalized
electrons are free
to flow through the
metal and so carry a
current.
delocalized electrons
Insulating materials
do not contain free
electrons and so
current is unable to
flow.
Keywords:
Voltage
Current
Electrons
Energy
transfer
Y8 T4 – Electricity and Electrical circuits
02/05/2017
3.Energy and Current
Objectives: To be able to distinguish between current and energy in an
electrical circuit.
Use what you have learned so far to answer these
questions
1.
Where does the energy in the circuit comes
from?
2. how energy lost from the circuit?
3. what particles carry the energy around the circuit
and where these particles come from?
4. Why batteries run out?
5. Explain why bulbs get dimmer when they are
connected in series and why does the current get
smaller when more bulbs are connected in series.
Keywords:
Voltage
Current
Electrons
Energy
transfer
Y8 T4 – Electricity and Electrical circuits
02/05/2017
3.Energy and Current
Objectives: To be able to distinguish between current and energy in an
electrical circuit.
We can think about electrical current like a water
system
water
pump
valve
(open)
narrow pipe
(harder for the water to flow)
Keywords:
Voltage
Current
Electrons
Energy
transfer
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
circuit.
Starter: The Diagram below shows a simple circuit
containing a battery and 2 different light bulbs.
V
V
?V
Keywords:
Branch
In parallel
Junction
6V
Draw the
diagram into
your exercise
book and fill
in the
missing
voltage (?V).
V
2V
Explain how
you worked
out the
answer.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
circuit.
Learning outcomes
-Level 4: identify in a circuit diagram when
components have been connected in parallel
-Level 5: Describe how current flows in a parallel
circuit.
-Level 6: Describe the relationship between
current through a cell and current through the
branches of a parallel circuit.
-Level 7: Make predictions about the currents
measured in a parallel circuit.
Keywords:
Branch
In parallel
Junction
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
circuit.
What is a series circuit?
Keywords:
Branch
In parallel
Junction
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
circuit.
What is a parallel circuit?
Keywords:
Branch
In parallel
Junction
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
Keywords:
Branch
In parallel
Junction
circuit.
Parallel circuits and switches
switch 1
M
motor
switch 2
mains power
supply
heater
If switch 1 was open (off position) and switch 2 was open (off
position), which components will switch on?
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
Keywords:
Branch
In parallel
Junction
circuit.
Parallel circuits and switches
switch 1
M
motor
switch 2
mains power
supply
heater
If switch 1 was closed (on position) and switch 2 was open (off
position), which components will switch on?
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
Keywords:
Branch
In parallel
Junction
circuit.
Parallel circuits and switches
switch 1
M
motor
switch 2
mains power
supply
heater
If switch 1 was closed (on position) and switch 2 was close (on
position), which components will switch on?
Try some on your own using worksheet J1b
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
circuit.
Task: You are going to carry out an investigation that
will help you work out the missing current reading in
the parallel circuit below.
A 2A
2A A
?A
A
A
?A
Keywords:
Branch
In parallel
Junction
Follow the
instructions
on
worksheet
7jc/2 and
use your
observations
to help you
fill in the
missing
currents.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
circuit.
Current in parallel circuits
Keywords:
Branch
In parallel
Junction
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
Keywords:
Branch
In parallel
Junction
circuit.
Max built circuit 1 as shown below
A
B
D
E
C
S
He closed the
switch, S, and
all the bulbs
came on.
One of the
bulbs then
broke and all
the bulbs went
off.
Which bulb
must have
broken?
Y8 T4 – Electricity and Electrical circuits
02/05/2017
4. Parallel circuits
Objectives: : Describe and explain how current flows through a parallel
Keywords:
Branch
In parallel
Junction
circuit.
Copy and complete the diagram by
using the information in the table
to label the bulbs with the
correct letter.
B
Disconnected
bulb
What happened
to the circuit
A
C & D stayed on B
switched off
B
C & D stayed on A
switched off
C
A, B and D
switched off
D
A, B and C stayed
on
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Starter: Draw the two circuits
below in your book and correctly
label them as in series or in parallel.
Which of the two circuits do you
think the light bulbs will be the
brightest. Write the answer in your
book and explain why you think this.
You will need your prediction later in
this lesson.
A
Keywords:
In parallel
In series
B
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Keywords:
In parallel
Observe in silence and complete the sentence:
In series
Current is the _______ all around a _______ circuit.
Potential difference is ______ between all ______ in series circuits.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Place Current
Experiment: 5 minutes!
Connect the circuits like the diagram
Find the current in Amps for each of
A1, A2, A3, A4 and A5
A1
What can you tell about the current
in series and parallel circuits?
A5
A2
Keywords:
In parallel
In series
A3
A4
B
A3
A
A1
A2
A4
A5
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Observe in silence and complete the sentence:
Potential difference is the _______ all around a _______ circuit.
Current is ______ between all ______ in parallel circuits.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Place
Objectives: : To compare how series and parallel circuits
work. Potential
Difference
Experiment: 5 minutes!
Connect the circuits like the diagram
Find the current in Amps for each of V1, V2, V3, V4,
V5 and V6
V1
What can you tell about the potential difference in
series and parallel circuits?
B
V5
V1
V2
V3
V4
V6
V1
V2
V2
V3
V3
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
DO THE STARTER TASK in SILENCE for VIVO’s; NOISY for C1, C2, C3…
Monday Keywords Starter: Book Page 128, 129
Find the meanings for 1 - 4
1. Parallel circuits – a circuit with more than one loop
2. Series circuits – a circuit with only one loop
3. Ammeters – a device measuring electronic current in a circuit
4. Voltmeters – a device measuring voltage/ potential difference
Find the keywords for 5 & 6
5. Each bulb still works even other bulbs are broken like lights
on Christmas trees. The light bulbs are independent
6. Potential difference is the same across each component in
parallel but is added up along each component in series.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Learning outcomes: copy each and leave 3 lines
in between
-Level 4: recognise series and parallel circuits in
circuit diagrams
-Level 5: Describe some advantages of parallel
circuits over series circuits.
-Level 6: Use the electron flow model to explain
the changes in current and voltage in series and
parallel circuits.
-Level 7: Make predictions about current and
voltages in series and parallel circuits.
Keywords:
Parallel circuits
Series circuits
Ammeters
Voltmeters
Independent
Potential
Difference
Current
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Keywords:
In parallel
In series
SUPER QUICK MULTIPLE CHOICE QUESTIONS!
•
•
•
•
02/05/2017
LET’s Challenge Ourselves!
You have 30 seconds at each question
You don’t need a calculator
Just check how much you have been
paying attention!
• Write down number 1 to 13
• ARE YOU READY!?
What kind of circuit is this?
Bulb
Parallel
Parallel &
Switch
series
Series
Not parallel
Wire
or series
What kind of circuit is this?
Bulb
Parallel
Parallel &
Switch
series
Series
Not parallel
Wire
or series
What kind of circuit is this?
Bulb
Parallel
Parallel &
Switch
series
Series
Not parallel
Wire
or series
Energy of the battery is
used up one after the other
in series circuits. What
adds up in components in
a series circuit?
Potential
Difference
Currents
Protons
Electrons
Current is how many charges
goes through the loop in each
second. There is only one loop
in series circuits. The current of
each component in series is…
Different
The same
Adds up
None of
the above
What is added up in components in
parallel, just like people walking
from 1 wide road to many smaller
roads and back on the 1 wide road.
Potential
Difference
Currents
Protons
Electrons
A battery giving electrical
energy to the charged particles
like pumping water up the hill.
How is energy pumped for
components in parallel to each
other?
Different
The same
Adds up
None of
the above
What is the missing potential
difference reading?
_ Volts
1 volt
0 volt
2 volts
0.5 volt
What is the missing potential
difference reading?
1 volt
0 volt
_ Volts
2 volts
0.5 volt
What is the missing current
reading?
1 amps
0 amps
_ Amps
2 amps
0.5 amps
What is the missing current
reading?
_ Amps
1 amps
0 amps
2 amps
0.5 amps
What is the missing current
reading?
2 Amps
_ Amps
1 amps
0 amps
2 amps
0.5 amps
What is the missing p.d.
reading?
2 volts
_ volts
1 amps
0 amps
2 amps
0.5 amps
What kind of circuit is this?
Bulb
Parallel
Parallel &
Switch
series
Series
Not parallel
Wire
or series
What kind of circuit is this?
Bulb
Parallel
Parallel &
Switch
series
Series
Not parallel
Wire
or series
What kind of circuit is this?
Bulb
Parallel
Parallel &
Switch
series
Series
Not parallel
Wire
or series
Energy of the battery is
used up one after the other
in series circuits. What
adds up in components in
a series circuit?
Potential
Difference
Currents
Protons
Electrons
Current is how many charges
goes through the loop in each
second. There is only one loop
in series circuits. The current of
each component in series is…
Different
The same
Adds up
None of
the above
What is added up in components in
parallel, just like people walking
from 1 wide road to many smaller
roads and back on the 1 wide road.
Potential
Difference
Currents
Protons
Electrons
A battery giving electrical
energy to the charged particles
like pumping water up the hill.
How is energy pumped for
components in parallel to each
other?
Different
The same
Adds up
None of
the above
What is the missing potential
difference reading?
_ Volts
1 volt
0 volt
2 volts
0.5 volt
What is the missing potential
difference reading?
1 volt
0 volt
_ Volts
2 volts
0.5 volt
What is the missing current
reading?
1 amps
0 amps
_ Amps
2 amps
0.5 amps
What is the missing current
reading?
_ Amps
1 amps
0 amps
2 amps
0.5 amps
What is the missing current
reading?
2 Amps
_ Amps
1 amps
0 amps
2 amps
0.5 amps
What is the missing p.d.
reading?
2 volts
_ volts
1 amps
0 amps
2 amps
0.5 amps
Y8 T4 – Electricity and Electrical circuits
02/05/2017
5.Series vs. Parallel Circuits
Objectives: : To compare how series and parallel circuits work.
Summary Task
1. Write one sentence for each of the
keywords.
2. Write sentences connecting different
keywords.
3. Write a story together with 1 other friend
with all the keywords.
Keywords:
Parallel circuits
Series circuits
Ammeters
Voltmeters
Independent
Potential
Difference
Current
Resistance in electric currents
02/05/2017
Objectives: : To understand how resistance in conductors affect
electric currents.
BELL TASK – Write the question number and the answers
Starter to do after you heard the starting bell of lesson
1. Where does the energy in the circuit comes
from? a power source such as batteries or power packs
2. how energy lost from the circuit?
any component that transfer the electric energy of the charges to another energy,
e.g. a light bulb changes electrical energy to light and heat energy
3. what particles carry the energy around the circuit
and where these particles come from?
electrons in the conductors, wires and components in the circuit
4. Why batteries run out?
Batteries only stores a certain amount of electrical energy
5. Explain why bulbs get dimmer when they are
connected in series and why does the current get
smaller when more bulbs are connected in series.
Potential difference (overall energy) of the power source is shared between light bulbs.
When more energy is required to light up more light bulbs at a time, less number of
charges can be pushed around.
02/05/2017
The higher the resistor setting, the stronger the
magnetic field.
The higher the number of coils, the stronger the
magnetic field.
Only iron core gives a strong enough magnetic field
attracting paper clips.
Think-pair-share: which one picked up the highest
number of paper clips?
Think about the THINGS that we checked that we can COUNT or
MEASURE…
02/05/2017
Let’s do one more
together before your
discuss questions in
groups of 2 people
YOU WON’T
GET A MARK!
02/05/2017
voltmeter
connected in parallel
How much energy is
transferred to
the charge
Draw the TABLE and FILL-IN the blanks
Y8 T4 – Electricity and Electrical circuits
02/05/2017
6.Electrical Safety
Objectives: : How can we use mains electricity safely at school and at
home?
Keywords:
Fuse
Heat energy
Light Energy
High voltage
How many hazards have
you seen.
Make a list of 5 things
we can do to make sure
we use electricity safely
as possible.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
6.Electrical Safety
Objectives: : How can we use mains electricity safely at school and at
home?
A fuse is a
device that is
used to protect
devices from a
current which is
too high.
Keywords:
Fuse
Heat energy
Light Energy
High voltage
When current gets to high the wire the current goes through gets hot.
Fuses contain pieces of conductor that melt if the current is too high.
When the fuse melts, it breaks the circuit.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
6.Electrical Safety
Objectives: : How can we use mains electricity safely at school and at
home?
This is the symbol for a fuse.
How do we know what fuse to use?
Keywords:
Fuse
Heat energy
Light Energy
High voltage
Fuses are labelled with the maximum current
they are designed to allow.
Rule:
When choosing the fuse for a device you should always
choose one with the ampage just above the operating
current of the device.
Y8 T4 – Electricity and Electrical circuits
02/05/2017
6.Electrical Safety
Objectives: : How can we use mains electricity safely at school and at
home?
Keywords:
Fuse
Heat energy
Light Energy
High voltage
Y8 T4 – Electricity and Electrical circuits
02/05/2017
6.Electrical Safety
Objectives: : How can we use mains electricity safely at school and at
home?
How does the thickness of the wire
affect the current a fuse can carry
before it blows?
You are going to carry out a quick
investigation to find out if large
current fuses have thicker or thinner
wires compared to low current fuses.
Follow the instructions on the sheet
and write down your observations.
Keywords:
Fuse
Heat energy
Light Energy
High voltage