Electricity Current Voltage Resistance Current, Voltage, Resistance characteristics AC DC Plugs Earth Fuses Power

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)

Circuit models Circuit diagrams Resistor models

IV Characteristics Resistor Bulb Diode

Resistors Thermistor LDR

review

Mains Elec PHET AC DC Period and frequency

Plugs

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

Earth What on Earth does it do? V d G

Earth No Earth – No Fault

Earth No Earth - Fault

Earth Earth – no Fault

Earth Earth - Fault

Power Power = work done / time taken Lifting stuff

Electrical Power Electrical power is the electrical work done in a given time. Power (W) = current (A) x voltage (V)