Radiation for life

Resistance 

variable resistor or rheostat changes resistance longer lengths of wire = more resistance  thinner wires = more resistance  voltage measured in volts using a voltmeter connected in parallel  fixed resistor - as voltage increases = current increasing  fixed power supply - as resistance increases = current decreasing  formulas:resistance = voltage/Current voltage = current x resistancecurrent = voltage/resistance 

Live, neutral and earth wires

live wire carries high voltage around house neutral wire completes the circuit providing a return path for the current  earth wire