Science - year 9 - electrcity

What is electricity?

Is the flow of electrons from 1 place to another.

Is electricty a secondary or primary energy source

Secondary source, it is converted form something else (sunlight, coal, oil)

What is static electricity?

An accumulation of charge

What is current electricity?

A flow of electrons

What are conductors and an example

Low resistance to Allow the flow of eletricity (eg metal)

What are insulators?

High resistance to Prevent the flow of electricity (eg rubber)

What is a simple circut

Consists of a power source, a conductor, and a load (like a lightblub.

Open circut

broken path; when the switch is off

Closed circut

complete circut - electricty only flows in closed circuts

Power souce example

Battery

Conducters example in the circut

Wires

Resistors example

A light bulb

Electricity is measured in

Volts for potential differeces, amps for current and ohms for resistance

Where does a voltmeter go in a circuit?

across a component outside of the circut

Where does the ammeter go in a circuit?

In the circut

V/I =

Resistance

V/R =

Current

I x R =

Voltage

Why is resistance important in a electric circut

To ensure the current flows at appropriate levels

Voltage

A measure of how much energy is given to each electron moving through a circut

Voltage drop

Across a component to see what is being used

Current

A measure of the rate electrons move through a circut

High Amps =

Lots of electrons

Low Amps =

Low amounts of electrons

increasing resistance

slows current

Increasing voltage

speeds up current

In a series circut =

Voltage is divided by the amount of loads

Current stays the same

In a parallel circurt =

Voltage stays the same

Current divides by the number of branches

Resistance

A material's opposition to the flow of electric current.

What are the uses of parallel circuts

The lights in our homes so that they can turn on some and not all.

how do you do the calculations in series circuts

Use the resistance levels of the whole circut

how do you do the calculations in parallel circuts

Use the resistance levels of the just the load

What are electrical hazards

Electrical connections not handled properly, may result in electric shock, burn, or other injury.

What is short circut

When the current takes an easier path that is unintended. This leads to an increase in the strength of the current resulting in fire or high heat

What is a circut breaker

When a current in a circut passes the saftey limit a circut breaker automatically switchs it off preventing danger

How do electrical sockets work

Current flows through the netural and active sockets some may include an earth pin into the wires to get rid of lose electricity

What is the role of the earth wire?

A wire that is found in home circuts and some appliances to safely dispose of electricity into the ground incase of a fault or short circut. In case of a short circut it would connect to the active pin making an even shorter