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701
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Unit 5P.5: Making electrical circuits
Electrical circuits
Designing circuits to solve
problems
Good and bad conductors
Enquiry Skills
Observing
Experimenting
By the end of this unit you should :
Construct simple circuits using bulbs, switches and
cells.
Know that electricity flows round a circuit from
positive pole of the cell to the negative one.
Test whether a material is a good conductor of
electricity.
Know the relationship between number of cells and the
brightness of bulbs.
701
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Exploring Circuits, what do you remember?
Get a simple torch light and take it apart, it may look
similar to this:
Can you Remember what each part is and what it
does?
Part Name What does it do?
A
B
C
connector
D
What happens if you put the batteries in a different
order? i.e
5.14.1, 5.14,2
A B
C
D
701
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Making Electrical circuits Activity: Make an electric circuit
Your teacher will organize the following materials for you:
Batteries, connecting wires, light bulb, sticky tape.
Steps:
- Light up the bulb using the battery and the conducting
wires.
- Draw a simple sketch showing you plan to do this:
Remove the battery and observe. What happens?
Where are the wires connected on the batteries and the
bulb?
How can you get the bulb to go on and off?
Each battery has two terminals that have two specific
signs (+, - ). Observe your battery and identify these
two signs. Label it below:
770
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
- Indicate the location of these signs on the sketch you
drew.
-Represent in your drawing the flow of current.
-What happens if you connect the two wires to the same
terminal?
________________________________________________
________________________________________________
Simple electric circuit
If you succeeded in lighting up the bulb
in the previous activity, then
congratulations!! You just created a simple
electric circuit.
An electric circuit provides a complete, closed path through
which the electric current flows.
777
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Here are some different types….
-What can you add to
this circuit to make it
easier to put the light on
and off?
____________________
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
-Label the parts of a simple electric circuit above, use the
following words:
a. What happens if one of these parts is not functioning?
________________________________________________
________________________________________________
b. What happens when the ‘switch’ is open?
________________________________________________
________________________________________________
c. What do you think would happen if you added 2 more
batteries!?
________________________________________________
________________________________________________
Bulb Wire Switch Battery
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Key Questions
1.a. The drawing below shows the
parts of a torch.
Ahmed closed the switch. Why
did this turn on the torch?
b. The drawings below show two other torches. In both
torches, the bulbs will not light even when Najib closes the
switches. Look carefully at the drawings.
i. Why is the circuit of torch
A not complete?
------------------------
------------------------
ii. What could you do to torch
B to get the bulb to light?
------------------------
------------------------
----
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
2. Look at each diagram and explain why the bulbs will not
light up.
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Types of electric circuit
When using more than one light
bulb in a circuit, the light bulbs
may be connected in series (one
after another) - in ONE LOOP.
Activity: Series Circuit
You will need:
- Battery (4.5 V)
-Two light bulbs (3-4.5 V)
-connecting wires
-switch
Steps:
- Set up the electric circuit as shown using all materials
mentioned above.
- Close the circuit by using the switch.
- Remove one of the two light bulbs. What happens?
________________________________________________
Activity: Parallel circuit
Series circuit: A circuit that connects several bulbs one
after another so that the current flows in a single path.
5.14.4
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
You will need: The same materials used in the previous
activity.
Steps:
-Set up the electric circuit as shown.
-Remove one of the two light bulbs. What happens?
--------------------------
---------------------------
Parallel circuit: a circuit
that connects several bulbs
in a way that the current
for each bulb has its own
path. (on separate
branches).
Key Words:
Series electric circuit
Parallel electric circuit
Key Ideas:
Using more than one light
bulb in circuit give us series
or parallel circuit.
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
2. Mark out the incorrect word in each of the following
sentences.
a) Two identical bulbs in a series circuit light together and
go out together/ light together but go out separately.
b) If one element in a parallel connection breaks down, all
other elements will continue to function/ will stop
functioning.
c) The same current/ different currents pass( es) through
two bulbs connected in series.
3. In this circuit, one bulb is unscrewed. (Taken out)
Will the other bulb glow? Explain your answer.
--------------------------------------------
Will the other bulb continue to glow?
---------------------------------------------
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Bulbs Brightness
Activity: What affects bulbs brightness?
You will need:
- 3 Batteries (4.5 V)
-Light bulb (4.5 V)
-Connecting wires
Steps:
-Try to light on 4.5 V light bulb using one
4.5V battery.
-Repeat the previous steps using two 4.5V battery then 3
batteries.
-Write down your observation for each trial.
Trial 1
Trial 2
Trial 3
Do you know now what affects the bulb brightness? How did
you know? ________________________________________
________________________________________________
5.14.4
771
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Demonstrating a bulb burning out
Add a fourth battery to the last circuit you created.
What did you observe now?
-------------------------------------------------
-------------------------------------------------
Be careful
Avoid situations where too much current passes through a
bulb, the bulb will burn out. This can be dangerous!
Increasing the number of bulbs in series in the circuit
makes bulbs shine less brightly.
Key Words:
Brightness
Key Ideas
Decreasing the number of cells
(battery) in series in a circuit will
make bulbs shine brighter.
Increasing the number of bulbs in
series in the circuit makes bulbs shine
less brightly.
Increasing the number of cells (battery) in series in a
circuit will make bulbs shine brighter.
710
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Key Question
Q1: Which of the circuits below give more light than the
circuit on the right?
Prediction: Result:
1- In which circuit will the
bulb be brightest?
2-In which circuit will the
bulb be the dimmest?
b- Why do you think this is? Explain your answer
----------------------------------------------
----------------------------------------------
717
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Designing circuits to solve problems
Good and bad conductors.
Material around can be divided into two groups according to
whether they allow the passage of the electric current or
not. Conductors include substances that allow the passage of
the electric current (Metals), while insulators include
substances that do not allow the passage of the electric
current.
Conductors: Substance that allow the passage of the
electric current (Metals).
5.14.3
Project
Work in group, to design and make circuits of your
choice that solve a problem. These may be circuits,
that model real situations (e.g. the light in a room) or
they may be circuits that perform a real function (e.g.
light up a bulb when someone steps on a mat, or ring a
bell when a door opens).
711
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Activity: Classifying substances into conductors and
insulators.
You will need:
Battery, light bulb, connecting wires, different kinds of
materials (paper, aluminum foil, plastic ruler, pencil, wood,
glass, copper wire, nail).
Procedure:
-Build a circuit similiar to that shown.
Insulators: Substance that Do Not allow the passage
of the electric current (Non-Metals).
Connect the material that
you want to test here.
E.g
711
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
-Connect one of the suggested substances as an additional
part to the electric circuit you built. Check if the light bulb
is still on.
i.e. testing a nail/screw
-Repeat the same step by using the other materials.
-Sort the substances as Conductors or insulators in the table
below.
Conductors
Insulators
What electrical appliances are made of?
Look at the following electrical appliances:
Radio Kettle Flash light Iron
711
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Complete the table for each and explain why certain parts
are conductors and other parts insulators.
Object Conductor Insulator
parts Why? parts Why?
Iron
Kettle
Radio
Flash
light
711
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
Key Words:
Conductor
Insulator
Key idea
Substances can be divided into two
groups according to whether they allow
the passage of the electric current or
not. (Conductors or Insulators).
Key Question
Put a tick (√) in the box if you think the bulbs will light up.
711
Physical Science
Grade5, Unit 5P.5:
Making electric circuit
2. a- Make a table with two columns. The first should have
the heading conductors and the second, insulators. Put the
following materials in the correct column in the table below.
Wool Glass
beaker
Coin Pencil
eraser
Plastic pen
Nail Wooden
ruler
Drawing
pin
Key
Insulators Conductors
b- How would you summarize what sort of materials are
conductors and which are insulators?
Conductors
Insulators
