Circuits & Electricity

Electricity

What makes the world BRIGHTER!

Open Ended

In your own words, describe what electricity is.

Electricity: the flow of electrical
power or charge. Based on the flow
of ELECTRONS.

Electricity is both a basic part of
nature and one of the most widely
used forms of energy.

In your notes, list as many items as you can which USE electricity:

CIRCUITS

A circuit is a closed loop that electricity flows through.

If the circuit is open, the electricity will flow through
the material.

If the circuit is closed, the electricity will NOT flow
through the material.

In order to keep the electricity flowing a voltage
difference, (example: battery), is required.

1.

OPEN

2.

CLOSED

Hotspot

Circle the closed circuit(s).

Batteries

Provide the voltage difference needed to keep
the electrons in a circuit flowing.

Current flows as long as there is a CLOSED path
which connects one battery terminal (positive
end) to the other battery terminal (negative end).

Types of batteries:
1.

Dry cell battery

2.

Wet cell battery

3.

Lithium-ion battery

Dry-cell

Household batteries

Wet cell

Car batteries

Lithium-ion

battery

Simple Circuits

Complex Circuits

Must have a source of voltage difference,
a device that has resistance, and
conductors that connect the voltage
difference to the resistor.

When these are connected, the electrical
current flows in the closed path.

Complex circuits have components that
are in series and some that are in
parallel.

If there is break in a complex circuit, not
all the components will go out. It will
depend on where the break in the
electron flow is located.

Series

Parallel

In a series circuit, components are
connected in a single path. Current
must go through every component
starting from the battery and back.

If there is a break in the component,
then the circuit will NOT work, because
there is no flow of electrons.

Contains two or more branches for
current to flow through.

If there is a break in the components will
remain lighted, because the electricity can
travel in an alternate direction

Draw

Label whether the circuits show are series or parallel.

YOU TRY!!!!

Is the circuit series or parallel? Explain your answer.

1

2

3

Circuit Symbols for drawing circuit diagrams

When creating circuit diagrams, symbols are used to represent the most common
features. These are just a few of the parts of circuit diagrams.

Battery

Motor

Resistor

Lamp

Single wire

Wire with intersection
wires

Voltmeter

Amp meter

Open Switch

End of Thursday's notes.

Please get the next simulation activity.

Match

Identify the types of circuites below.

series

open

closed

parallel

complex

• series

• open

• closed

• parallel

• complex

Electric Current

Voltage Difference

The movement of electric charges in a
single direction.

Always flows from positive to negative.

Measured in Amperes (Amps)

One amp = 6250 million billion electrons
flowing past a point every second

Electric current is the speed electrons
flow.

The force that causes electrons to flow.

Just as water flows from high to low
pressure, so do electrons. The
difference between the high and low
pressure is the voltage.

It is measured in volts.

Voltage is the "push" of electrons.

Resistance

Conductors & Insulators

The tendency of a material to oppose
the flow of electrons.

Resistance changes electrical energy
into another form of energy.

With very few exceptions, all materials
have some electrical resistance.

Resistance is measured in ohms
We use the Greek letter omega to
represent ohms →Ω .

Electrical conductors have less resistance
than insulators.

Resistance increases as the temperature
of the material increases.

Resistance increases as length of the wire
increases.

Resistance decreases as the width of the
wire increases.

EX: Conductors--Metals, sea water

Insulators--Glass, plastic, rubber, etc

Ohm’s Law

The relationship between voltage difference, current, and resistance.

I = Current (Amps)
V= Voltage Difference (Volts)
R = Resistance (Ohms)

I =V
R

Electrical Power

The power used depends on the voltage difference and the current.

P = Power (Watts)
I = Current (Amps)
V = Voltage Difference (Volts)

P = I *V

Electric Energy

Rate at which electrical energy is converted into other forms of energy

E = Energy (kW or kiloWatt)
P = Power (Watt)
t = time (hours)


E = P * t