AC & DC

• Alternating current

  Current that reverses its direction
• Direct current

  Current that always travels in the same direction around a circuit
• What creates an alternating current

  An alternating voltage, for example from mains electricity
• What creates a direct current

  Direct voltage, for example from a battery or cell
• Mains electricity

  Generated by power stations and delivered to homes via the national grid. This is accessed by plugging devices into wall sockets
• Frequency of mains electricity

  50 Hz
• Voltage of mains electricity

  230-240 volts
• What will an oscilloscope trace look like for an alternating current

  Look for the same current and voltage
• What will an oscilloscope trace look like for a direct current


  Current could either be positive or negative depending on which way the current is travelling.

  The trace would look the same for both current and voltage