PL AR RS P5L32 Electrical System 6 WS

Primary 5

Rocket Science

Name: ___________________________________________________
Tutor: _________E_L_E_C__T_R_IC__A_L__S_Y_S_T_E__M__6_(_L_E_S_S_O__N__3_2_) __________
Topic:
ELECTRICAL SYSTEM 6 (LESSON 32)

Primary 5: Rocket Science

Lesson Outline
• Notes
• Activity 1: Hands-on Activity
• Activity 2: MCQS
• Activity 3: Open-ended Questions
• Activity 4: Fun Facts

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Primary 5: Rocket Science

Series and Parallel Circuit - Notes
There are two ways to arrange the components of an electric circuit. Each has
different effect in the current and in the load.
A circuit in which the components are connected from end-to-end are called
___________. This provides a single path for ___________ or the flow of
electrons. The bulbs in this circuit share an equal current. So, if you have two
bulbs, current will be divided equally to the two bulbs.

AR Model – Circuit

Series circuit

Since electricity flows from the source Series circuit with one bulb busted
to each load one at a time, in the Light produced in series circuit
order they are wired to the circuit, if
one of the bulbs blew out, the other
bulbs would not be able to light up.
This is because the current is
interrupted and the circuit is open.

Adding more batteries in a series
circuit will produce _______ light.
While adding more bulbs will produce
________ light this is because the
bulbs in a series divides the electric
current more, thus, each light will
receive less current.

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Primary 5: Rocket Science

Series and Parallel Circuit - Notes
In _______ circuit, there are multiple paths through which electrons can flow.

Parallel Circuit
In this circuit, the electric current has more than one path to travel. So, if one
bulb fuses, the other bulb would still be able to _________because the current
will still flow to the good bulb.
Each bulb receives the same amount of current that leaves the battery. Current is
not divided into the number of bulbs or loads. Adding more bulbs will not affect
the current and all bulbs will have the same brightness. However, this will
consume battery faster than it is in a series circuit.
Adding more batteries in this circuit will give brighter light but there is a limit. The
bulbs have limited current capacity. If there is too high current flowing though the
bulb it might fuse. Thus, before adding more batteries take a look at the limit of
current that the bulb can hold to avoid getting busted.

Which circuit do you think is the best to put
in this extension sockets? Why?
____________________________________
____________________________________
____________________________________

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Primary 5: Rocket Science

VIDEO: Circuits in Household

https://www.youtube.com/watch?v=tHnPCS8NWfI
Guide Questions:
1. What are the types of circuit?
2. Which type of connection/circuit do appliances and devices at home have?
2. Why are circuits at home parallel?

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Primary 5: Rocket Science

Activity 1 – Hands-on Activity: Series and Parallel Circuit Simulation
Material:
Phet.colodaro.edu simulation for electric circuit
Link: https://phet.colorado.edu/sims/html/circuit-construction-kit-dc-virtual-
lab/latest/circuit-construction-kit-dc-virtual-lab_en.html
Instructions:
1. Create the circuit diagram below in the simulation. Make sure to set the

battery for each circuit to 9-Volts and all the bulb in the same resistance
10-Ω. Set this by clicking the object. Observe the light in each circuit.
Write your observation below.

Circuit B
Circuit A
___________________________________________________________
___________________________________________________________

2. Disconnect one bulb in Circuit A. Do the same in Circuit B. Write your
observation here.
___________________________________________________________
___________________________________________________________

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Primary 5: Rocket Science

3. Add one more bulb in each circuit. Observe what happens in the current
and brightness of the bulbs.
____________________________________________________________
____________________________________________________________

4. Add another 9-Volts battery to Circuit A. Do the same in Circuit B.
Observe what happens to the brightness of the bulbs and the current.
_____________________________________________________________
_____________________________________________________________

(a) How would you differentiate the flow of electrons or the current of each
circuit?
__________________________________________________________
__________________________________________________________

(b) How does the number of bulb affect Circuit A and Circuit B?
__________________________________________________________
__________________________________________________________

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Primary 5: Rocket Science

(c) How does adding more batteries affect the circuit? Is it always better
to add many batteries?
__________________________________________________________
__________________________________________________________

(d) Which circuit will consume the battery faster?
__________________________________________________________
__________________________________________________________

(e) Differentiate the flow of current in Circuit A and Circuit B.
__________________________________________________________
__________________________________________________________

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Primary 5: Rocket Science

Study the circuits below and observe the brightness of the bulbs.

Circuit W Circuit X

Circuit Y Circuit Z

(f) Which circuit will produce a brighter light between Circuit X and Circuit Z?
__________________________________________________________
__________________________________________________________

(g) Arrange the circuit from the brightest to the dimmest.
__________________________________________________________
__________________________________________________________

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Primary 5: Rocket Science

Activity 2 - MCQs

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Primary 5: Rocket Science

1. A battery powered toy gun is shown below. When the trigger is pulled, the
toy gun makes a sound and the tip of the gun lights up.

Part that lights up trigger
when trigger is
pulled

Which of the following could be a possible circuit of the toy gun?

sound
(1) player

sound player
(2)

(3) sound
player

(4) sound player

()

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Primary 5: Rocket Science

2. Study the diagram below.

All the bulbs were lit when all 4 switches are closed. Which switch would you choose if
you want to have the fewest number of bulbs lit by using only 1 switch?
(1) S1
(2) S2
(3) S3
(4) S4

()

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Primary 5: Rocket Science
3. The diagrams below show different circuit diagrams S, T, U, and V.

ST UV

Which of the following shows correctly the arrangement of the bulbs from dimmest to the
brightest?

(1) S, V, U and T )
(2) S, T, U, and V
(3) T, U, V, and S
(4) V, S, U, and T

(

4. The following circuits have different arrangement but used identical batteries
and lamps. The lamps in all circuits lighted up.

K LM
N

Which of the following statements about the brightness of the lamps is correct?

(1) Lamps M is brighter than lamp K
(2) Lamp N is brighter than lamp M
(3) Lamp K is brighter than lamp L
(4) Lamp L is brighter than lamp M

()

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5. Study the diagram below. Primary 5: Rocket Science
AB C

All the bulbs are identical and lit up when the switch was closed.
Which bulb, when removed from its bulb holder, will cause the remaining bulb not to light
up?

(1) A
(2) B
(3) C
(4) D

()

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Primary 5: Rocket Science

6. A student carried out an experiment to find out how the number of bulbs
added in series will affect the brightness of the bulbs in a circuit. The results
are recorded in the table below.

Number of Batteries Number of bulbs Brightness of bulbs
added in series
1 Bright
1 1 Dim
1 Dimmer
2

3

Based on the table, which one of the graphs shows the result correctly?

(1) (2)

brightness brightness
of bulbs of bulbs

Number of bulbs Number of bulbs

(3) (4)

brightness brightness
of bulbs of bulbs

Number of bulbs Number of bulbs

()

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Primary 5: Rocket Science

7. Which of the following are correct about electrical usage?
A. Worn out cable should not be used.
B. Putting hot food in the refrigerator will not affect the amount of electricity used.
C. It is safe to touch switches with wet hands because switches are made of
insulating materials.
D. To save electricity, we should use the fan more than the air-conditioner, as the
fan uses less electricity.

(1) A and D only
(2) B and C only
(3) A, C and D only
(4) B, C and D only

()

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Primary 5: Rocket Science

8. A student wanted to find out the effects of the arrangement of the bulbs to
its brightness. The student made four circuits using identical components
as shown below.

Circuit W Circuit X

Circuit Y Circuit Z

Which two circuits should the student use to carry out a fair test?

(1) W and Y
(2) W and X
(3) X and Y
(4) X and Z

( )

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Primary 5: Rocket Science

9. Study the diagram below.
S2

S1 Buzzer

S3

Which of the following switch(es) should be closed so that the buzzer and only one bulb will
light up?

(1) S2 only
(2) S3 only
(3) S1 and S3 only
(4) S1 and S2 only

()

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Primary 5: Rocket Science

10. Which of the following statement(s) is/are the possible reason(s) for us to
conserve electricity?

A. Using excessive electricity may cause a fire at home.
B. The fossil fuel needed to generate electricity is limited.
C. Burning fossil fuels to generate electricity pollutes the environment

(1) A only
(2) A and C only
(3) B and C only
(4) A, B, and C

( )

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Activity 3: Open-ended questions

1. Jim used some light bulbs, batteries, wires and switches to construct 2 electrical circuits,

A and B. He used the same number of identical batteries and light bulbs in both the
circuits. When one of the bulbs fused in both circuits, he found that only the remaining
bulb in circuit A remained lit while both bulbs did not light up for circuit B.

(a) (i) In the diagram below, complete the circuits to show how Jim could have [1]
constructed the 2 circuits.

(ii) In some electrical products where many light bulbs need to be connected together,

the light bulbs are also arranged in the same way as in circuit A above. Explain why

it is advantageous to do so. [1]

________________________________________________________
________________________________________________________

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An electromagnetic door lock as shown below is commonly used in buildings to keep
the doors locked.

power source part A
wire coils part B

steel bars

(b) Explain how parts A and B work to keep the door closed. [2]

_________________________________________________________

_________________________________________________________

_________________________________________________________

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Primary 5: Rocket Science

2. Identical bulbs and batteries were used in the circuit diagram shown below.

S2

B1 B2

S1
B3

The switches are then closed.

(a) What happens to bulbs B1 and B3 when bulbs B2 fuses? Explain your

answer. [2]

_________________________________________________________

_________________________________________________________ [1]
(b) Which switch should be opened so that all bulbs will still light up?

_________________________________________________________

_________________________________________________________

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Primary 5: Rocket Science

ACTIVITY 4: FUN FACTS | How to squeeze electricity out of crystals?

https://www.youtube.com/watch?v=YEJ2qryXcIQ Answer
Discuss

Before the video What is piezoelectricity?

0.17 How can a simple crystal
0:20 such as sugar act like a tiny
1:51
3.45 power source?

What is a piezoelectric
material?

What makes a material
piezoelectric?

What are the applications of
piezoelectric materials?

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