Mains electricity

How do insulation double insulation earthing fuses and circuit breakers protect users and appliances

Insulation: covers wires with non conductive materials to prevent shocks

Double insulation: plastic castings Dont need earth wires so reduces electric shock risk

Earthing: directs excess current into the ground if the live wire touches the casting

Fuses : the wires melts when current is too high breaking the circuit and preventing overheating

Circuit breakers: automatically switch the circuit off of the current is too high

How is power related to selecting appropriate fuse

Fuse tips must be slightly above the value

Why does current in a resistor result in energy transfer and increased temperature

When current flows through a resistor electrical energy is converted into heat energy due to resistance

What is the equation for power

Power = current x voltage

What is the equation for energy transferred in an electrical circuit

Energy = current x voltage x time

What is the difference between alternating current and direct current

AC: constantly changes direction

DC: flows in one direction