ElectricityCurrentVoltage
ResistanceCurrent, Voltage, Resistance characteristics
AC DCPlugsEarthFusesPower
Current
• Current is the amount of charge flowing past a point in a given time
Current (A) = Charge (C) / time (s)
Current read by an ammeter – connected in series
Potential Difference
• Voltage• Potential difference is the energy
given to or given by a charge when it passes a component.
PD (V) = Energy (J) / Charge (C)
PD is taken by a voltmeter and is connected in parallel with the
component.
Resistance
• Resistance is the volts per amp for a component.
• How many volts are needed to push a current of so many through a component.
Resistance (Ohms) = PD (V)/ Current (A)
Fuse• A Fuse is a piece of wire with a low
melting point• If there is a fault in the electrical
appliance and the current goes up it could damage the wiring in the appliance
• But if a fuse is installed, this will melt (or “blow”) and break the circuit
• So a fuse is used to protect the appliance – not necessarily to protect us from electric shock