Alternating current and direct current

• What are the two types of current you need to know about?

  Alternating current (AC) and direct current (DC)
• How does alternating current (AC) behave?

  The direction of the current constantly swaps
• What causes alternating current to fluctuate?

  Alternating potential difference or voltage
• What does measuring potential difference over time show in AC?

  It fluctuates between negative and positive
• What type of current is supplied by UK mains electricity?

  Alternating current (AC)
• What is the frequency of UK mains supply electricity?

  50 hertz
• What is the voltage of UK mains supply electricity?

  Around 240 volts
• What does the voltage fluctuate between in UK mains supply?

  Positive 240 volts to negative 240 volts
• How many times does the current fluctuate in UK mains supply every second?

  50 times
• Why might you hear the voltage referred to as 230 volts instead of 240 volts in the UK?

  Both values are correct for exams
• How does direct current (DC) behave?

  The charge flows in the same direction
• Where do we typically find direct current (DC)?

  In cells and batteries
• What type of potential difference produces direct current?

  A direct potential difference
• What devices are used to display potential difference graphs?

  Oscilloscopes
• What are the characteristics of alternating current (AC)?

  • Direction constantly swaps
  • Produced by alternating voltage
  • Fluctuates between positive and negative
  • Commonly used in mains electricity
• What are the characteristics of direct current (DC)?

  • Charge flows in the same direction
  • Produced by direct voltage
  • Found in batteries and cells
• What is the significance of oscilloscopes in electrical measurements?

  • Display potential difference graphs
  • Show voltage changes over time