Circuit Diagrams

Electrical Circuits

There are two types of electric charge:

Positive
Negative

Protons

Electrons

Atom

Circuits

A circuit is a complete circular path that electricity flows
through.

Power Source

Globe

Switch

Wire

Circuit Diagrams

Circuit Diagrams are used to show the electric components
within a circuit and how those components are arranged.

In circuit diagrams, internationally accepted symbols are
used to represent each circuit component.

Straight lines are used to represent the wire loads connecting
the components.

Circuit Diagram Rules:

When you are drawing Circuit diagrams, you MUST:

• Use pencil

• Draw straight lines with a ruler

• Label each component

Electric Circuit Symbols

Wire

Resistor

Cell

Battery

Light Globe

Ammeter

A

V
Voltmeter

2 Wires Joined

Open Switch

Closed Switch

Draw

Draw the symbol for a battery

Draw

Draw the symbol for a light

Switches

Open Switch

Closed Switch

Off

On

Series Circuits

In a torch, the batteries, globe and switch are connected one
after the other. Conductors, including the metal strip, link the
components.

The circuit is a single, complete loop.

Globe

Series Circuit

Multiple Choice

This circuit has 2 lamps. If I add another lamp to this series circuit, the lamps will shine..

• brighter

• dimmer

• stay the same.

Multiple Choice

What kind of circuit is this?

• series

• parallel

Series circuits are simple to put together; however, if
any part of a series circuit does not work, such as
one of the globes in the diagram below, none of the
circuit will work.
A series circuit does not work even if one part breaks
down.

Draw

Draw a series circuit with a battery, light, and a open switch

Parallel Circuits

Imagine what would happen if the electrical appliances in your
home were all connected in series?

Every time a light blows out, no other electrical appliance would
work.

To avoid this problem, most circuits contain components
connected parallel. This means that each component is
connected in a separate parallel path. A parallel circuit works
even when one part of it breaks down.

Parallel Circuits

A parallel circuit has more than one path for the electricity to
follow. If one of the paths is broken, the other paths will still work.
Only components in the broken part of the circuit will stop working.

Multiple Choice

This is an example of a ______ circuit

• Series
• Parallel
• Open
• Dihexihedral

Multiple Choice

What kind of circuit is this?

• Series
• Consecutive
• Parallel
• Training

Multiple Choice

What kind of circuit is this?

• series
• parallel

Series

Parallel

Series
circuits:

single loop / no branches

If you put more lamps into a series circuit, the
lamps will be dimmer than before.

different components are connected on
different branches of the wire

• Components on

different branches keep
working if components
on another branch
breaks

• The lamps stay bright if

you add more lamps in
parallel

Parallel

The ammeter

The ammeter is a device that measures electric current, which is
the ‘rate of change’ flow through a circuit. The more electrons that
flow through the circuit per second, the higher the current and the
higher the ammeter reading.

The ammeter is always connected in a series, this way, the
electrons that flow through the circuit will also flow through the
ammeter.

The voltmeter

The energy provided to electrons as they move around a circuit is
supplied by a battery or other power source. As the electrons
move around the circuit, some of their electrical energy is
transformed into other forms of energy by the components in the
circuit, which act as a load. The electrical energy that is
transformed by components along the circuit is measured in volts
using a voltmeter.

Hotspot

Using the diagram provided, identify the switch.

Multiple Choice

In which of the circuits will the bulb light up?

• Circuit A

• Circuit B

• Circuit C

• Circuit D

Multiple Choice

Pick the correct sentence.

• This circuit will work because it is a closed circuit.

• Energy will freely flow in this circuit.

• This circuit will not work because there is no energy source.

• This circuit will not work because there is no switch.

Match

Match the following

Bulb

Ammeter

Voltmeter

Switch

• Bulb

• Ammeter

• Voltmeter

• Switch

Multiple Choice

Choose the correct sentence.

• This circuit will work because it is an open circuit.
• This circuit will work because it is a closed circuit.
• This circuit will NOT work because it is an open circuit.
• This circuit will NOT work because it is a closed circuit.

Hotspot

Which lamps will light up? Select all the lamps that will light up.

​Flow of Electricity in a Circuit

​Electricity can only flow if the switch in the circuit is closed.

​

​Electricity will continue to flow until it hits a resistor.

​

​Resistor- an object where electricity flows through slowly.

​Electrical energy transforms in a resistor.

COPY ALL
What are resistors?

●Resistor
○ Object that uses electrical energy as interferes with or ‘resists’ the current
■Either converts electricity to heat or light energy

●Resistance
○ How much energy is slowed down by a material

**The greater the resistance, the less current or amps there is flowing for a given
voltage.

Multiple Choice

What units do we work with when it comes to resistance?

• amps

• light years

• volts

• ohms

What do Amperes measure?

●Amps- Also called Amperes
○Amps- Also called Amperes

○Measure the amount of electrical CHARGE or CURRENTMeasure the amount
of electrical CHARGE or CURRENT

Multiple Choice

Which one, top or bottom, offers more resistance?

• top
• bottom
• neither

Multiple Choice

What does this symbol represent?

• NC Switch

• NO Switch

• Resistor

• Transistor

• Battery

Categorize

Options (6)

Material that keeps electricity from flowing

Rubber, Glass, or Plastic

Materials that allow electrons to flow freely

Copper, Silver, metals

Uses electrical energy and converts energy into heat or light

Light bulb

Sort the answers as either insulators, conductors, or resistors.

Insulators

Conductors

Resistors

Multiple Choice

What are the color codes for a 470K ohm resistor?

• Orange, Grey, Orange

• Yellow, Violet, Brown

• Yellow, Violet, Orange

• Orange, Grey, Yellow

Categorize

Options (6)

Only 1 path for electricity to flow

In batteries add amps and volts

In lights dims lights and if one goes out all go out

Multiple paths for electricity to flow

For batteries, keeps the same amps and volts, but lasts longer

For lights, all equal brightness and stay lit if one goes out

Sort the options into either series or parallel categories.

Series Circuit

Parallel Circuit

Poll

How confident do you feel regarding electrical energy and creating electrical circuits?

• I do not understand any of this

• I understand some parts

• I need to practice in one more lesson

• I understand it all

Poll

Are you ready to complete a practical?

• Not really

• 100% - let's do this!