grade 9 electricity

Charging by friction

Occurs when two different neutral materials are touched together and electric charges are transferred from one object to the other

Neutral

Same number of positive charges in the same number of negative charges

Electrostatic series

The material that is higher on the list will lose electrons and become positive and the material that is lower on the list will gain electrons and become negative

Charging by conduction

Is charging an object by contact with a charged object it can also involve touching a neutral object with a charged object or touching two charged objects together. The neutral object will always receive the same charge as the charged object.

Grounding

Connecting an object to a large body like the Earth that is capable of effectively removing the electric charge that the object might have

how an electric scope works

when an uncharged object touches the sphere of the electroscope or is brought close to it, but does not touch it. The lease will do nothing. When I charged object come close to or touches the sphere of the microscope the metal leaves began to repel each other because the two leaves have the same charge. This is not matter whether it is positive or negatively charged

Law of electric charge

Like charges repel each other while opposite charges attract each other

Switch

Controls the circuit by turning it on or off

A load or any electrical device

Transformed electrical energy into other types of energy

Connect connecting wire

Provide the path for the electrons to flow

Source of electrical energy

Supplies, electrical energy

Series circuit

There’s only one path three electrons to flow

Parallel circuit

There is more than one path for the electrons to flow. The electrons that leave the source are divided between the loads.

Electrical current

A measure of the rate of electron flow passed the given point in a circuit.

Symbol: I

Device: ammeter (connected in series)

Unit of measurement: Amperes/ amps/ a

“counting runners going past a water station.”

Potential difference (voltage)

The difference of the amount of energy, the electrons have at two different points.

Symbol: V

Device used to measure: voltmeter (connected in parallel)

Unit of measurement: volts/ v

“ energy gained by an electron going through a battery.”

Resistance

The ability to impede (try to stop or slow) the flow of electrons

Symbol: R

Device used to measure: ohmmeter

Unit of measurement: OHMS (o)

“ skiing through deep snowing on a groomed trail.”

Electrical resistance

when electrons flow through a load, the electrical resistance causes a loss of electrical potential (voltage). voltage is lost or dropped across the load (voltage drop).

Factors that affect resistance include the type of material, cross-sectional area length and temperature

Type of material

Affects how easily electrons can move. Some

Have higher resistance than others

Changing by induction

Charging without touching by bringing a charged object nearby

Cross-sectional area

thinner wire = more resistance

Length

longer wire = greater resistance

Temperature

higher temperature = higher resistance because atoms vibrate more making it harder for electrons to move

Energy conversions

When electricity meets resistance, the electrical energy is changed into one of four types of energy: light energy, heat, energy, sound, energy, and mechanical energy

ohms law

States that the electrical current through a conductor between two points is directly proportional to the voltage across two points.

Electric current

Electrons have energy because they are pushing it right from other electrons in attracted to positive charge if a conductor gives electrons an easy pass they will move from a place within a negative charge to a place with a positive charge. The flow of electron is called electric current.

Ammeter

A device which measures current in a circuit, an ammeter must be connected in series with the circuit so that electrons can flow through the metre this device council electrons that run through it.

Electrical potential

The amount of energy that each electron has is called the electrical potential of the electron. The amount of energy electron gains or loses between two points is called the electrical potential difference between the points.

voltmeter

This device is connected parallel to the component. It is measuring the voltage of it needs to measure energy before and after the component.

What subatomic particle is fixed in place in a nucleus of an atom

Proton

To become positively charged an atom has to..

Lose electrons

A negatively charged object has… electrons than protons

More

Which direction do electrons move in a circuit?

-to+

What is the difference between a conductor and an insulator?

A conductor is a material that easily allows electrons to flow through while an insulator prevents electron flow

What are the main parts of a simple circuit?

Power source - battery

Conducting path - wire

Load device. - light bulb