ch.12.less.5.how do we use electricity and magnetism (part 1)
DESCRIPTION
circuits, conductors and insulators and types of electricity.TRANSCRIPT
HOW DO WE USE ELECTRICITY AND MAGNETISM? (PART 1)Chapter 12: Lesson 5:
WHAT IS MATTER?Matter is everything around us that has
mass and volume
Recap
WHAT IS MATTER MADE OF?
Matter is made of very small building blocks called ‘ATOMS’
WHAT ARE ATOMS?
•Smallest part of any matter•Cannot be seen with a normal microscope (use electron microscope)
•Example:Oxygen CarbonN.B. Water (H₂O)is made of 1 atom of oxygen and 2 atoms of hydrogen)
WHAT DO ATOMS LOOK LIKE?
ATOMS…
•Have neutrons, protons, and electrons.•Protons are positively (+) charged •Electrons are negatively (-) charged
Positive and Negative Charge
Opposites charges attract
Same charges repel
STATIC ELECTRICITY
•The build up of an electric charge on the surface of an object.
•The charge builds up but does not flow.•Static electricity does not move. It is stored.
EXAMPLES OF STATIC
ELECTRICITY
Try rubbing a balloon against a wool cloth
Place the balloon over anybody’s hair
and watch what happens
1) BALLOON EXPERIMENT
When we rub the balloon against a
wool cloth, the balloon gains a
negative charge (-)
The (-) charge in the balloon attracts the
(+) charge in the hair causing the hair to
stand.
EXPLANATION
Try rubbing a comb against a wool cloth
The comb will gain a negative charge
Bring the comb near some pieces of paper
2) COMB EXPERIMENT
Initially the paper is uncharged, but the comb attracts the positive
charges in the paper and repels the negative charges.
Rubbing of rain drops and ice inside a
storm cloud
When the (-) charges get large enough they jump to the ground as
lightning.9
3) LIGHTNING(IS CAUSED BY)
CURRENT ELECTRICITY
(CURRENT ELECTRICITY)•A flow of electrical charges through a circuit.
(Circuit is a path along which electric current flows)
Circuits should have 3 parts
Power sourceBattery (cell)
LoadBulb / Motor
ConnectorsWires
Power source
Load
Connectors
Types of circuits
Open circuitsBroken circuits (Incomplete)
Closed circuitsUnbroken circuits
(Complete)
CIRCUITS’ SYMBOLS:
1) Battery
2) Bulb
3) Wires
(A straight line)
4) Switch (off)
5) Switch (on)
6) Motor
7) Buzzer
SERIES AND PARALLEL CIRCUITS
SERIES CIRCUIT
• Series circuit - has only one path through which the electricity can flow.
• In the above diagram, the electricity flows through both loads.
PARALLEL CIRCUITS
• A parallel circuit has multiple paths through which the electricity can flow.
• In a parallel circuit, the current though one path may be different than the current through the other path.
PARALLEL CIRCUIT
• Place two bulbs in parallel. What do you notice about the brightness of the bulbs?
• Add a third light bulb in the circuit. What do you notice about the brightness of the bulbs?
• Remove the middle bulb from the circuit. What happened?
SIMPLE CIRCUITS
• Series circuit• All in a row• 1 path for electricity• 1 light goes out and
the circuit is broken
• Parallel circuit• Many paths for
electricity• 1 light goes out and
the others stay on
Conductors and Insulators
A conductor is a substance through which electric charge flows readily. An insulator is a substance that strongly resists the flow of electric charge.