ScienceYear 7 Physics

Electricity

Notes & Experiments

Name:________________Teacher:______________

YOU MUST KEEP THIS BOOK

[INSERT SCHOOL LOGO HERE]

MY UNDERSTANDING CHECKLIST

I can… Textbook Page

Before the Topic

After the Topic

Drawing CircuitsIdentify 5 circuit components by their symbol 64 – 67 Sketch a circuit diagram using the correct component symbols 64 – 67

Tell the difference between a series and parallel circuit from a circuit diagram 68 – 69

Measuring CurrentState that current (I) is measured in Amps (A) and is measured using an Ammeter 64

Describe current as the ‘flow of charge’ from the positive end of a power source to the negative end

64

Describe how current is the same everywhere in a series circuit but splits in a parallel circuit 68 – 69

Measuring VoltageState that voltage (V) is measured in Volts (V) using a Voltmeter connected in Parallel. 66 – 67

Describe how voltage is the same everywhere in a parallel circuit but splits in a series circuit 69

Explain the advantages of using parallel circuits over series circuits. 68

ResistanceState that resistance (R) is measured in Ohms (Ω) 70

Use the equations V=IR to calculate resistance 70 – 71 Describe how you can calculate the resistance in a circuit but measuring current and voltage 70

Stretch Lesson: Building a Fire AlarmDescribe what is meant by a ‘bimetallic strip’ -Explain why a bimetallic strip acts like a switch an a circuit -

Build a fire alarm and explain how it works -

MY SKILLS CHECKLIST

I can… Before the Topic After the TopicDraw circuit diagrams from a physical circuitBuild a circuit from a circuit diagramConnect a Voltmeter in Parallel to take readings.Set up a circuit which contains both an Ammeter and a Voltmeter

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KEY WORDS

Some of the key words and definitions are missing some information! Can you complete them?

Key Word Image/Diagram Definition

Circuit

A complete ________ which current (electricity) flows around.

Component

A name given to the pieces of equipment that make up a _______.

Component Symbol

A _______ used to represent a _________ in a circuit diagram.

Circuit Diagram

A collect of _____________ _________ connected together which show how a circuit should be set up.

A circuit where there is only one loop of wire

A circuit with two or more branches that split apart and join up again. (multiple loops)

Current

The flow of _______ from the positive terminal to the ____________ terminal of a power supply. It is measured in ______ (A)A way of saying how much energy is transferred per unit charge. It is measured in Volts (V)

Resistance

A measure of how difficult it is for ________ to flow through a circuit or component. We measure it in _________ ( )

Ammeter

A device used to measure the __________ (in _________) in a circuit. It must be connected in ______ to the circuit.

VoltmeterA device used to measure __________ (in _______) across a component. It must be connected in ________ across a

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component.

Lesson 1: Drawing Circuits

LEARNING OBJECTIVES:DEVELOPING IDENTIFY 5 CIRCUIT COMPONENTS BY THEIR SYMBOLS SECURE SKETCH A CIRCUIT DIAGRAM USING THE CORRECT

COMPONENT SYMBOLS

EXTENDING TELL THE DIFFERENCE BETWEEN A SERIES AND PARALLEL CIRCUIT FROM THE CIRCUIT DIAGRAM

SCIENTIFIC SKILLS DRAW CIRCUIT DIAGRAMS FROM A PHYSICAL CIRCUIT

Do Now: Drawing Components

Using your creativity, can you think of a quick and simple way to draw these electrical components?

Can you think of any other electrical components that we might use?

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STRETCH

Sketch Sketch

Motor

Resistor

Component Symbols

In physics, we want to be able to draw circuit diagrams that are quick to sketch and simple to read. This lead to the creation of component symbols.

Work through the table with your teacher to learn about the components and their symbols.

Component Name

Picture Component Use Symbol

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Circuit Diagrams

Now that we know the component symbols, we just need to put them together! We call this a circuit diagram. Think of it as a recipe to follow when building a circuit.

Worked Example:

Draw the circuit diagram for the following circuit.

Circuit Diagram:

Things to remember:

1. Make sure all lines are joined up. 2. Use a ruler for wires3. We draw circuits as squares and rectangles not as circles.

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Useful Circuit Builder Animation: https://phet.colorado.edu/sims/html/circuit-construction-kit-dc/latest/circuit-construction-kit-dc_en.html

Worksheet: Circuit Diagrams

Have a go at drawing the circuit diagrams for the following circuits.

Circuit 1:

Circuit 2:

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Circuit Diagram Circus

Work your way around the room and observe the circuits. Can you draw themin the boxes below using the correct symbols?

Circuit A Circuit B

Circuit C Circuit D

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Stretch Circuit

Series vs. Parallel

There are two types of circuit. These are

1.

2.

The easiest way to tell the difference between them is to count the number of ‘loops’:

If there is just one ‘loop’ then the circuit is a series circuit. If there is more than one ‘loop’ then the circuit is a parallel circuit.

Circ

uit

Type Series Parallel

Circ

uit D

iagr

am

Exam

ple

Num

ber o

f Lo

ops

9

Adv

anta

ges

Dis

adva

ntag

es

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In the space below design your own circuit using the components you learnt about today.

Underneath explain what it does.

…………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………….

STRETCH

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In the space below design your own circuit using the components you learnt about today.

Underneath explain what it does.

…………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………….

…………………………………………………………………………………………………………………………………………………………….

Lesson 2: Measuring Current

LEARNING OBJECTIVES:DEVELOPING STATE THAT CURRENT (I) IS MEASURED IN AMPERES

“AMPS” (A) AND IS MEASURED USING AN AMMETERSECURE DESCRIBE CURRENT AS THE ‘FLOW OF CHARGE’ FROM

THE POSITIVE END OF THE POWER SOURCE TO THE NEGATIVE END

EXTENDING DESCRIBE HOW CURRENT IS THE SAME EVERYWHERE IN A SERIES CIRCUIT BUT SPLITS IN A PARALLEL CIRCUIT

SCIENTIFIC SKILLS BUILD A CIRCUIT FROM A CIRCUIT DIAGRAM

Do Now: Spot the Mistake

Can you find the mistakes in the table below? Correct them in green pen.

[Hint: there are 6 to find]

Notes: What is Current?

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Component Image Component Name Component

Symbol

Bulb

Fuse

Connectors

Cell

Machine

- +

Complete the blanks below with the help of your teacher.

Key Ideas about Current

Current is a measure of the rate of flow of ________ in a circuit Current travels from the ______________ to the ____________ terminal of the

power source. Current can only flow if the circuit is complete. Current has the symbol ____ and is measured in _________ (A). We can use an ammeter to measure the value of the current in a circuit. In the space

below draw the component symbol for an ammeter?

On the circuits below, add arrows to indicate the direction of the current:

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

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Health and Safety Check!

Keep hands dry and make sure all equipment is in good working order

Investigation: How does current behave?

Current is measured using an _____________.

When you are connecting ammeters, they must be connected in series. This means they are in line with the other components.

Current in Series

Start by setting up the circuit below:

TASK: Can you add arrows to show which direction the current is flowing in?

Complete the table below by reading the ammeters in the circuit:

Ammeter Current (A)

A1

A2

A3

Do you notice any patterns?

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

Current in Parallel

Start by setting up the circuit below:

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TASK: Can you add arrows to show which direction the current is flowing in?

Complete the table below by reading the ammeters in the circuit:

Ammeter Current (A)

A1

A2

A3

A4

Do you notice any patterns?

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

Notes: Current in Series and Parallel

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Use the following table to summarise your notes on the behaviour of current in both Series and Parallel circuits.

Circ

uit

Type Series Parallel

Circ

uit D

iagr

am E

xam

ple

Expl

ain

the

beha

viou

r of

the

curr

ent?

Exam

ple

A1 =

A2 =

A3 = A1 =

A2 =

A3 =

A4 =

Worksheet: Current in Series and Parallel

For the following circuit diagrams

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1. State if it is a series or parallel circuit 2. Identify the direction of current flow3. State the missing values of each ammeter

Assume all light bulbs are of equal resistance.

PEER MARKScore [ /16]: Next Steps:

Assessed Worksheet: Drawing Circuits

For each of the Circuits below, produce a circuit diagram with correct component symbols. Remember to use a ruler.

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1. 2.

3. 4.

CG Score: Next Steps:

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There are three houses and three suppliers: gas, water, and electricity. Aim of the game: Draw lines to get each utility into every house, without crossing

over any line.

STRETCH

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There are three houses and three suppliers: gas, water, and electricity. Aim of the game: Draw lines to get each utility into every house, without crossing

over any line.

Lesson 3: Measuring Voltage

DEVELOPING STATE THAT VOLTAGE (V) IS MEASURED IN VOLTS (V) USING A VOLTMETER CONNECTED IN PARALLEL

SECURE DESCRIBE HOW VOLTAGE IS THE SAME EVERYWHERE IN A PARALLEL CIRCUIT BUT SPLITS IN A SERIES CIRCUIT

EXTENDING EXPLAIN THE ADVANTAGES OF USING PARALLEL CIRCUITS OVER SERIES CIRCUITS

SCIENTIFIC SKILLS CONNECT A VOLTMETER IN PARALLEL TO TAKE READINGS

Do Now: Year 7 Quick Quiz

Can you use your knowledge from Forces, Motion and Energy to answer the following questions?

1. What is the resultant force on the following box? [2]

……… ………..

2. What is the mass of an object on Earth that has a weight of 125N? Assume g = 10N/kg [3]

3. What is meant by a balanced force? [1]

………………………………………

………………………………………

4. What is the Energy Chain for a burning candle? [3]

5. What are the units of Energy? [1]

………………………………………

6. Give one example of a non-renewable energy resource and 2 examples of renewable energy resources. [3]

………………………………………

………………………………………

………………………………………

Score [ /13]

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Notes: What is Voltage?

Complete the blanks below with the help of your teacher.

Key Ideas about Voltage

Voltage is defined as the energy transferred per unit _____________. Voltage has the symbol ____ and is measured in _________ (V). Voltage is also commonly referred to as _________ difference. The power source (cell or battery) of a circuit provides the voltage to the circuit. As the current flows around the circuit voltage is transferred to different

components. We can use a voltmeter to measure the value of the current in a circuit. In the space

below draw the component symbol for a voltmeter?

REMEMBER: A Voltmeter is always connected in parallel.

On the circuit below, add 2 voltmeters:

1. To measure the voltage across the cell. (V1)2. To measure the voltage across the lamp. (V2)

……………………………………………………………………………………………………………………………………………….

………………………………………………………………………………………………………………………………………………

21Health and Safety Check!

Keep hands dry and make sure all equipment is in good working order

Investigation: How does Voltage behave?

Voltage is measured using a _____________.

When you are connecting voltmeters, they must be connected in parallel. This means they will create an extra loop in your circuit.

Voltage in Series

Start by setting up the circuit below:

TASK: Highlight the Voltmeter which is measuring the voltage across the battery.

Complete the table below by reading the voltmeters in the circuit:

Voltmeter Voltage (V)

V1

V2

V3

Do you notice any patterns?

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

Voltage in Parallel

Start by setting up the circuit below:

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Complete the table below by reading the voltmeters in the circuit:

Voltmeter Voltage (V)

V1

V2

V3

Do you notice any patterns?

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

THINK: Why might it be better to use a parallel circuit for lights instead of a series circuit?

……………………………………………………………………………………………………………………………………………….

……………………………………………………………………………………………………………………………………………….

Notes: Voltage in Series and Parallel

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Use the following table to summarise your notes on the behaviour of current in both Series and Parallel circuits.

Circ

uit

Type Series Parallel

Circ

uit D

iagr

am E

xam

ple

Expl

ain

the

beha

viou

r of

the

volta

ge?

Exam

ple V1 =

V2 =

V3 =

V1 =

V2 =

V3 =

Worksheet: Voltage in Series and Parallel

For the following circuit diagrams

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1. State if it is a series or parallel circuit 2. State the missing values of each Voltmeter

PEER MARKScore [ /16]: Next Steps:

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3.4.

Assessed Worksheet: Series and Parallel Circuits

For the following circuits complete the missing Ammeter/Voltmeter readings

CG Score: Next Steps:

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Lesson 4: Resistance

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STRETCH

DEVELOPING STATE THAT RESISTANCE (R) IS MEASURED IN OHMS (Ω)

SECURE USE THE EQUATION V=IR TO CALCULATE RESISTANCE

EXTENDING DESCRIBE HOW YOU CAN CALCULATE THE RESISTANCE IN A CIRCUIT BY MEASURING CURRENT AND VOLTAGE

SCIENTIFIC SKILLS SET UP A CIRCUIT CONTAINING BOTH AN AMMETER AND A VOLTMETER

Do Now: Connecting Components

Add the following to the circuit below to measure the current through and voltage across the lamp:

1. Ammeter2. Voltmeter

Explain your placement.

…………………………………………………………………………………………………..

…………………………………………………………………………………………………..

…………………………………………………………………………………………………..

…………………………………………………………………………………………………..

…………………………………………………………………………………………………..

…………………………………………………………………………………………………..

Notes: What is Resistance?

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Complete the blanks below with the help of your teacher.

Key Ideas about Resistance

Wires and other components in a circuit reduce the ___________ through them. This is called ______________.

Resistance is a measure of how difficult it is for ________ to flow through a circuit or component.

Resistance has the symbol ____ and is measured in _________ (Ω). Practice drawing the ‘Ohm’ symbol below:

As you add more components to a circuit, the resistance of the circuit __________.

In order to measure Resistance, we must measure 2 things:

1. Voltage2. Current

On the diagram below show how you could measure both of these:

Calculating Resistance: Ohm’s Law

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Once we have the Current (I) through and the Voltage (V) across a component we can calculate the Resistance (R) of that component.

Voltage, Current and Resistance are linked by the following equation know an Ohm’s Law

Voltage (V )=Current ( I )× Resistance(R)

Which can be represented in the following equation triangle:

Worked Example:

A Light Bulb has 5A of current flowing through it. The Voltage across the Light Bulb is measured to be 20V. Calculate the Resistance of the Light Bulb:

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Calculations: Voltage, Current and Resistance

Can you use the equation triangle to answer the following questions?

1. An alarm clock draws 0.5 A of current when connected to a 120 volt circuit. Calculate its resistance.

2. A 12 Volt car battery pushes charge through the headlight circuit resistance of 10 ohms. How much current is passing through the circuit?

3. An electric heater works by passing a current of 100 A though a coiled metal wire, making it red hot. If the resistance of the wire is 1.1 ohms, what voltage must be applied to it?

4. If a toaster produces 12 ohms of resistance in a 120-volt circuit, what is the amount of current in the circuit?

5. What current flows through a hair dryer plugged into a 120 Volt circuit if it has a resistance of 25 ohms?

PEER MARKScore [ /15]: Next Steps:

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Investigation: Measuring Resistance

To measure the Resistance in a circuit I mustmeasure:

1. ________________ (A)2. ________________ (V)

To calculate the resistance, I will use the equation:

Method:

1. Set up the circuit shown above2. Change the component x 3. Measure the current from the Ammeter4. Measure the voltage from the Voltmeter5. Calculate the Resistance6. Change component x and repeat.

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x

Health and Safety Check!

Keep hands dry and make sure all equipment is in good working order

Results: Measuring Resistance

Component Symbol Voltage (V)

Current (A)

Resistance (Ω)

Lamp

Resistor

Motor

Switch

Buzzer

Conclusions from your investigationUse your investigation results to answer the following questions:

1. Which of the Components had the highest resistance?

2. What does this mean for the current through this component?

3. Which of the components has the lowest resistance?

4. What does this mean for the current through this component?

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In the Word search below there are 18 words linked to Electricity.

Can you find them are write clue for them below?

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STRETCH

Lesson 5: Building a Fire Alarm

DEVELOPING DESCRIBE WHAT IS MEANT BY A ‘BIMETALLIC STRIP’ SECURE EXPLAIN WHY A BIMETALLIC STRIP ACTS LIKE A SWITCH IN

A CIRCUITEXTENDING BUILD A FIRE ALARM AND EXPLAIN HOW IT WORKS. SCIENTIFIC SKILLS SAFELY USE A BUNSEN BURNER

Do Now: Labelling a Diagram

Can you label the apparatus on the diagram below?

………………………………………………………………………………………………...

………………………………………………………………………………………………...

………………………………………………………………………………………………...

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STRETCH

Investigation: Building a Fire Alarm

In this investigation you are going to build a model of a Fire Alarm.

You are going to be using a bimetallic strip.

In your own words describe what a bimetallic strip is:

………………………………………………………………………………………………...

………………………………………………………………………………………………...

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Health and Safety Check!

Do not touch bimetallic strip when it is hot.

Wear goggles and tie away loose hair and clothingwhen using a Bunsen

Conclusions: Answer the questions below in as much detail as you can.

1. Why did you need to clean the bimetallic strip?………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...

2. How could you adjust the fire alarm so the light came on sooner? Explain your answer.………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...

3. How could you change your circuits so that the bulb was on, and went off when the bimetallic strip got hot? Explain your answer. ………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...

4. Describe in your own words how the fire alarm works. ………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...………………………………………………………………………………………...

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Electricity: Past Paper Questions

Q1. Ben makes a series circuit using two identical cells, a bulb and a switch to turn the bulb on and off.

(a) Draw a circuit diagram of Ben’s circuit. Use the correct symbols.

The cells have been drawn for you.

3 marks

(b) Which part of the circuit supplies the energy?

......................................................................................................................1 mark

(c) Ben adds another identical bulb to the circuit in series.How does the brightness of the first bulb change?

......................................................................................................................1 mark

(d) How will the brightness of the bulbs change when the cells shown below are placed into Ben’s circuit?

(i)

.............................................1 mark

(ii)

.............................................1 mark

maximum 7 marks

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Q2. Nina’s bicycle has a front lamp and a rear lamp.Both lamps are connected to the same battery.

(a) The circuit diagram for the lamps is drawn below.

(i) On the circuit diagram above, place a letter A to show the position of aswitch to turn only the front lamp on and off.

1 mark

(ii) On the circuit diagram above, place a letter B to show the position of aswitch to turn both lamps on and off at the same time.

1 mark

(b) Nina replaces the battery with a generator called a dynamo.When Nina pedals her bicycle, the back wheel turns the generator.

Complete the sentences below using words from the box.

chemical electrically gravitationalkinetic light radiation thermal

As Nina pedals, ..................................... energy in her muscles is

transferred to kinetic energy.

When the generator turns, kinetic energy is transferred …………………. in the wires.

This energy in then transferred usefully by .................................... in the bulb.

When the lamps are on, some of the energy in the bulb is wasted as

..................................... energy.4 marks

maximum 6 marks

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Q3.(a) Draw a line from each electrical circuit to the correct circuit diagram.

Draw only four lines.

electrical circuit circuit diagram

2 marks

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(b) In each circuit below, bulb 1 breaks and goes off.

Under each circuit diagram below, tick the correct boxes to show if bulb 2 and bulb 3 are on or off.

circuit A circuit B

2 marks

(c) Give the name of the part that provides energy for each circuit.

........................................................1 mark

(d) Why is copper used for wires in a circuit?Tick the correct box.

1 mark

maximum 6 marks

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XX

Q4.Susan has a small fan to keep herself cool.When she switches it on, a motor turns the blades to blow air.

(a) The diagrams below show the symbols for a battery, a motor and a switch.

In the space below, draw a series circuit diagram for the fan using thesesymbols.

1 mark

(b) (i) Which part provides energy for the circuit?

.........................................................1 mark

(ii) Some of this energy is used to turn the blades.The rest of the energy is wasted.

Complete the sentence below. Choose words from the list.

chemical thermal radiation sound1 mark

When the blades are turning, energy is wasted as

....................................... energy and by ......................................1 mark

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(c) Susan built a circuit using a battery, a motor and a switch.She closed the switch to turn the motor on.

(i) Susan added a bulb to the circuit.The current in the circuit decreased.

How did this affect the motor?

.............................................................................................................1 mark

(ii) Susan removed the motor from the circuit.The current in the circuit increased.

How did this affect the bulb?

.............................................................................................................1 mark

maximum 6 marks

Q5.Some pupils made an electric cell using two different metals and a lemon.They put strips of copper and zinc into a lemon and connected them to the terminals ofan electric clock.

(a) Look at the photograph.

What evidence is there that they have made an electric cell?

................................................................................................................1 mark

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(b) The pupils had pieces of copper, zinc, iron and magnesium and some lemons.They wanted to find out which pair of metals made the cell with the biggestvoltage.

What equipment should they use to measure the voltage of their cells?

................................................................................................................1 mark

(c) In their investigation they used different pairs of metals.

Give one factor that they should keep the same.

................................................................................................................1 mark

(d) The pupils measured the voltage produced by different pairs of metals.Their results are recorded below.

Which pair of metals made the cell with the biggest voltage?

..................................... and ..............................................1 mark

(e) Look at the results in the table above.

Why should the pupils not use pairs of the same type of metal for the clock?

................................................................................................................

................................................................................................................1 mark

maximum 5 marks

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Q6.A pupil makes some electrical circuits.Each circuit contains a motor and a buzzer.The motor and the buzzer can be switched on or off by three switches, A, B and C.

Symbols for an open switch and a closed switch are shown below.

By each circuit diagram, state whether:

the motor is on or off;the buzzer is on or off.

(i)

The motor is ................................

The buzzer is ................................

1 mark

(ii)

The motor is ................................

The buzzer is ................................

1 mark

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(iii)

The motor is ................................

The buzzer is ................................1 mark

(iv)

The motor is ................................

The buzzer is ................................1 mark

Maximum 4 marks

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Q8.(a) The diagram below shows a circuit with a two-way switch, S.

Rosie puts the switch in the position shown below.

Complete the table below to show if the bulbs are on or off.Write on or off for each bulb.

bulb on or off

P

Q

R

1 mark

(b) Give the name of the part that provides energy for the circuit.

.............................................................1 mark

(c) The diagrams below show a lightbulb over a staircase of a model house.

There is a two-way switch at the bottom of the stairs and another two-way switch at the top.

Under each diagram, tick one box to show if the bulb is on or off. The first one has been done for you.

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2 marks

maximum 4 marks

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