mains electricity (safety features in domestic appliance)

What are the five things that wires contain to make them more safe

insulated

double insulated

earth wire

fuses

circuit breakers

how is insulation in wires make wires more safe

wires are covered in plastic (plastic is the insulator) this prevents the person touching the actual live wires.

how is double insulation in wires make wires more safe

around the wires it has plastic AND insulated wires to make sure there is no wires exposed for people to touch.

how does an earth wire make wires more safer

if the live wire touches the metal case, the earth wire will make the current flow into the earth to prevent an electric shock.

how do fuses make wires more safer

it is a wire, when the current is too high the fuse melts.

how do circuit breakers make wires more safer

detects a surge in a current and automatically switches the circuit off

what do I mean by surge

sudden increase on the current.

what happens in a resistor

when electrons in the current collide into the resistor, it converts from electrical energy to thermal energy. This makes the resistance increase, and also the temperature increase for the resistor.

give me three examples of what things contain a resistor

kettles

toasters

hairdryers

what is the formula for power

Current x voltage

what is the formula for energy transferred

Current x voltage x time

define alternating current

it is supplied by mains electricity and current constantly changes direction

define direct current

it is supplied by batteries and cells and the current flows in one direction only.