Electricity and Magnetism

ELECTRICITY &

MAGNETISM

Introduction

AGENDA

01

03

04

02

05

06

07

08

09

10

What is

Electricity?

Law of
Electric
Charges

Static

Electricity

Electric
Currents

Conductors &

Insulators

Electric
Circuits

What is

Magnetism?

Magnetic

Fields

Electro-magn

ets

MAGNETISM CAN CREATE ELECTRICITY

ELECTRICITY &
MAGNETISM

ELECTRICITY CAN PRODUCE MAGNETISM

When charges from one piece of

matter interact with those from

another piece of matter, they

produce both electric and magnetic

forces.

ELECTRICITY IS THE INTERACTION OF ELECTRIC

CHARGES.

WHAT IS ELECTRICITY?

Electric charges are a fundamental property of protons and

electrons, which make up every atom. Positive and negative

charges are the two types of electric charges. Protons possess

a positive charge, whereas electrons carry a negative charge.

Multiple Choice

What is electricity?

• an object that electrons do not flow through

• energy created by moving charged particles

• when two objects repel each other

• a circuit that has only one path for electricity to flow

LAW OF ELECTRIC
CHARGES

LIKE CHARGES REPEL

UNLIKE CHARGES ATTRACT

THE ELECTRIC FORCE IS THE ATTRACTION OR

REPULSION BETWEEN CHARGED OBJECTS.

The size of charges and the distance between

them are both key factors in determining the

strength of the electric force between charged

objects.

COULOMB'S LAW

Multiple Choice

Which two particles are attracted to each other?

• Two neutrons

• A proton and an electron

• Two protons

• An electron and a neutron

Multiple Choice

A repulsive force exists between which two particles?

• Two neutrons

• An electron and a neutron

• An electron and a proton

• Two protons

Multiple Choice

As two oppositely charged particles approach each other, what happens to the electrical force between them?

• The attractive force increases

• The magnitude of the electric force decreases

• The repulsive force increases

• The magnitude of their charges increases

STATIC

ELECTRICITY

THE BUILD UP OF ELECTRIC CHARGES ON AN OBJECT

When you rub a balloon against your hair, electrons

from the atoms that make up your hair transfer to the

balloon, which makes your hair positively charged due

to electron loss. The balloon becomes negatively

charged due to electron gain. When you hold the balloon

several centimeters from your head, your hair stands

up due to the attraction between the two opposite

charges.

ELECTRIC DISCHARGE

Have you ever received a shock when you touch a metal

doorknob after shuffling your feet on the carpet? That is

an example of electric discharge on a small scale.

Can you think of an example of electric discharge on a larger scale?

The charges that build up on an object do eventually move off

the object. This sudden and brief flow of electrons is called:

Multiple Choice

What charge does a proton have?

• negative (-)
• positive (+)
• neutral or no charge (0)

Multiple Choice

What charge does an electron have?

• negative (-)
• positive (+)
• neutral or no charge (0)

Multiple Choice

If a substance has a higher number of electrons than protons on its surface, what type of charge does it have?

• A positive charge.
• A negative charge.
• A neutral charge
• No charge at all

Multiple Choice

Which of the following is caused by static electricity?

• a stove getting hot when it is turned on
• a magnet being attracted to a refrigerator
• a lightning strike during a storm
• a light bulb coming on when a switch is turned on

Multiple Choice

An object becomes postiively charged when which of the following occurs?

• loses electrons
• gains electrons
• loses protons
• gains neutrons

ELECTRIC CURRENT

CURRENT ELECTRICITY IS A CONTINUOUS FLOW OF ELECTRIC

CHARGE

Current is defined as the quantity of charge that flows past a given point per

unit of time. The standard unit of measurement for current is the ampere (A).

DIRECT CURRENT (DC)

ALTERNATING CURRENT (AC)

A type of electric current where the charges flow in one

direction only. Batteries are an example of a direct current

source.

A type of electric current that flows in one direction, then the reverse

direction, repeatedly. The electric current supplied by power

companies to homes is an example of AC.

Multiple Choice

Current is...

• moving protons
• moving electrons
• measured in volts
• measured in ohms

Multiple Choice

Metals such as copper and aluminum are good ______________. 

• insulators
• conductors
• circuits
• charges

Multiple Choice

The two types of current are...

• AC/DC
• Alternating Current
• Direct Current
• All of the above

CONDUCTORS &
INSULATORS

Conductors are materials that allow

an electric current to flow through

them easily, while insulators are

materials that resist the flow of

electric current.

• Rubber

• Glass

• Plastic

Examples of Insulators:

• Air

• Wood

• Paper

CONDUCTORS &
INSULATORS

Conductors are materials that allow an

electric current to flow through them

easily, while insulators are materials that

resist the flow of electric current.

• Metals such as copper, aluminum, silver, and gold

• Water (when it contains dissolved salts or other

charged particles)

• Graphite (found in pencils)

• Human body (can conduct small amounts of electric

current)

Examples of Conductors:

Explanation Slide...

The main difference between conductors and insulators is that conductors allow the flow of electricity, while insulators do not.

Multiple Choice

What is the main difference between conductors and insulators?

• Conductors allow the flow of electricity, while insulators do not.

• Conductors are always solid, while insulators can be liquid or gas.

• Conductors are always transparent, while insulators are always opaque.

• Conductors allow the flow of water, while insulators do not.

Explanation Slide...

Metals have free electrons that can move easily through the material, allowing electricity to flow.

Multiple Choice

Explain why metals are good conductors of electricity.

• Metals have no free electrons to conduct electricity.

• Metals are good conductors because they are insulators.

• Metals have a high resistance to the flow of electricity.

• Metals have free electrons that can move easily through the material, allowing electricity to flow.

Explanation Slide...

Electrons facilitate the flow of electric current by carrying the charge through the conducting material.

Multiple Choice

What is the role of electrons in conducting materials?

• They facilitate the flow of electric current.

• They repel electric current

• They have no effect on electric current

• They absorb electric current

Explanation Slide...

Insulators do not conduct electricity because their electrons are tightly bound, preventing the flow of electric current.

Multiple Choice

Why do insulators not conduct electricity?

• Tightly bound electrons

• Low resistance

• Loose electrons

• High conductivity

Explanation Slide...

Conductors such as electrical wiring, metal utensils, and metal pipes are commonly used in everyday life for various purposes.

Multiple Choice

What are some common uses of conductors in everyday life?

• Electrical wiring, metal utensils, metal pipes

• Glassware, ceramic plates, cardboard boxes

• Plastic utensils, rubber pipes, wooden furniture

• Paper clips, rubber bands, plastic bags

Explanation Slide...

Understanding conductors and insulators helps in identifying materials that can conduct electricity and pose a risk of electric shock, as well as materials that can insulate and prevent electrical hazards.

Multiple Choice

Discuss the importance of understanding conductors and insulators in electrical safety.

• Understanding conductors and insulators is only important for environmental protection

• It helps in identifying materials that can conduct electricity and pose a risk of electric shock, as well as materials that can insulate and prevent electrical hazards.

• Conductors and insulators are only relevant in mechanical safety

• It has no impact on electrical safety

ELECTRIC
CIRCUITS

ENERGY SOURCE

LOAD

SWITCH

WIRES

PARTS OF A CIRCUIT

• Energy source: An electric field created by a

battery's positively and negatively charged

terminals attracts and repels charges,

providing the push to keep them moving

through a closed circuit.

• Load: A component in a circuit that consumes

electrical energy to perform a function, such

as generating light or motion, and resists the

flow of electric current, causing a voltage

drop.

ELECTRIC
CIRCUITS

ENERGY SOURCE

LOAD

SWITCH

WIRES

PARTS OF A CIRCUIT

• Wires: A low-resistance conductor that carries

current in a circuit, connecting components.

Material and thickness are selected based on

distance, current, and voltage for efficient and

safe operation.

• Switch: A switch controls a circuit by connecting

or disconnecting two metal pieces. When the

pieces touch, the circuit closes; when they

separate, the circuit opens.

TYPES OF CIRCUITS

CURRENT FLOWS THROUGH A CLOSED

CIRCUIT, A LOOP WITH NO BREAKS, BUT AN

OPEN CIRCUIT HAS A BREAK AND STOPS THE

CURRENT FLOW.

There are several options for connecting multiple

loads in a circuit. Here are the two of the most

common approaches:

• Series circuit: This involves connecting the loads in

a line or series, allowing the current to flow from

one load to the next in a single path.

SERIES

TYPES OF CIRCUITS

CURRENT FLOWS THROUGH A CLOSED

CIRCUIT, A LOOP WITH NO BREAKS, BUT AN

OPEN CIRCUIT HAS A BREAK AND STOPS THE

CURRENT FLOW.

PARALLEL

There are several options for connecting multiple loads

in a circuit. Here are the two of the most common

approaches:

• Series circuit: This involves connecting the loads in

a line or series, allowing the current to flow from one

load to the next in a single path.

• Parallel circuit: Here, the loads divide the current

amount of the different devices, creating a parallel

connection.

Multiple Choice

If you replace the paper clip with a plastic spoon, what happens?

• The bulb doesn't light
• The bulb is dimmer
• The wires get hot
• There is no change

Multiple Choice

What kind of circuit is this?

• series
• parallel

Multiple Choice

this is the symbol for a _____?

• switch
• light 
• battery
• wires

Multiple Choice

What kind of circuit is this?

• Series
• Consecutive
• Parallel
• Training

Multiple Choice

If the electric circuit is CLOSED, the switch is _______. 

• ON
• OFF

Multiple Choice

If the electric circuit is OPEN, the switch is ____.

• ON
• OFF

V

I

R

OHM'S LAW

Ohm's Law describes the relationship between

electric current and voltage in a conductor, stating

that the amount of electric current flowing through a

conductor is directly proportional to the voltage

that is causing the current to flow.

• I is the current (measured in

amperes)

• V is the voltage (measured in volts)

• R is the resistance of the conductor

(measured in ohms)

Divide V by R to find the current.

Divide V by I to find resistance.

A force that can attract or repel certain

materials, such as iron, and is caused by the

movement of electric charges within certain

objects, like magnets or electric currents.

WHAT IS MAGNETISM?

Magnets attract iron and have two poles, a negative

and a positive pole, where the magnetic force is

strongest. All magnets share these properties.

LIKE CHARGES REPEL

UNLIKE CHARGES ATTRACT

N

S

N

N

N

N

N

S

S

S

S

S

MAGNETIC FIELD

THE REGION AROUND A MAGNET THAT IS AFFECTED BY

MAGNETIC FORCES.

N

S

WHAT DO YOU THINK IT MIGHT LOOK LIKE?

N

S

MAGNETIC FIELD

THE REGION AROUND A MAGNET THAT IS AFFECTED BY MAGNETIC

FORCES.

Earth's magnetic field is what makes compasses

work? The needle of a compass is a tiny magnet

that aligns with the Earth's magnetic field, pointing

north-south. This is possible because the Earth

itself acts as a giant magnet thanks to its magnetic

core, which generates a magnetic field that extends

far into space. This field is what protects us from

the solar wind and other harmful particles that

constantly bombard our planet. Without it, life on

Earth as we know it would not be possible.

DID YOU KNOW?

Multiple Choice

Where is the force of a magnet the strongest?

• at the magnet's poles

• in the middle of the magnet

• far away from the magnet

Multiple Choice

What is a magnetic domain?

• a region in a magnetic material in which the magnetic fields of atoms all point in the same direction

• a region in a magnetic material in which the magnetic fields of atoms all point in different directions

Multiple Choice

What does the strength of a magnetic force depend on?

• how close an object is to the magnet

• the size of the magnet

• what the magnet is made of

• all of the above

Multiple Choice

Which of the following shows the magnetic field correctly around a bar magnet?

• Diagram A

• Diagram B

• Diagram C

• Diagram D

Multiple Choice

We know the substance in the image is magnetized because ___.

• All the domains are at right angles to each other.

• All the domains are aligned.

• All the arrows are drawn in red.

• All the domains are not aligned.

Multiple Choice

This substance is ___.

• magnetized

• positively charged

• negatively charged

• unmagnetized

Multiple Choice

How do magnetic field lines move?

• always from the south pole towards the

  north pole

• always from the north pole towards the

  south pole

• always from the pole to the middle

• depends of the type of magnet

Multiple Choice

Which answer describes the pictures correctly?

• Both drawings show attraction of magnetic forces.

• The left drawing shows repulsion and the right drawing shows attraction of magnetic forces.

• Both drawings show repulsion of magnetic forces.

• The left drawing shows attraction and the right drawing shows repulsion of magnetic forces.

To produce a strong magnetic field, wrap coils of wire around an

iron rod. Current passing through the coils of wire magnetizes the

rod, producing a powerful magnet, called an electromagnet. The

more loops in the coil the stronger the magnetic field.

ELECTROMAGNETISM

Physicist Hans Christian Oersted was the first to discover

that electric current produces a magnetic field around a

wire.

Electromagnets are used in

electric motors, loudspeakers,

television sets, doorbells, trains,

and many other devices.

The process of creating an electric

current by moving a conductor

through a magnetic field or by

varying the magnetic field around

it.
The majority of the electricity

supplied to homes is generated

using electromagnetic induction.

Faraday's

Electromagnetic

Induction

Multiple Choice

When running a current through a wire, what do the blue lines represent?

• The wire spinning

• A magnetic field that was created

• Electrons leaving

• Electricity

Multiple Choice

Generators are devices that convert _____ energy into _____ energy.

• chemical; mechanical
• mechanical; electrical
• electrical; mechanical
• potential; kinetic

Multiple Choice

A _______________ is a current-carrying coil of wire with many loops.

• magnet

• electromagnet

• solenoid

• compass

Multiple Select

What is/are the difference(s) between a magnet and an electromagnet? (two correct choices)

• An electromagnet can be turned on/off.

• A magnet can be turned off.

• An electromagnet is stronger.

Multiple Choice

How can a magnet be used to produce an electric current?

• Hold a magnet next to a piece of wire.

• Wrap wire around a magnet.

• Spin the magnet around inside a coil of wire.

Multiple Choice

Which of the following is not a good conductor?

• Copper

• Silver

• Aluminium

• Plastic

UNIT TEST ON

Friday, Feb. 14th