Alternating (AC) and Direct Current (DC)

• What are the two types of current mentioned?

  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 electricity?

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

  Around 240 volts
• How does the potential difference fluctuate in UK mains electricity?

  From positive 240 volts to negative 240 volts
• How many times does the potential difference fluctuate per second in UK mains electricity?

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

  Both values are correct in the UK
• What is direct current (DC) produced by?

  A direct potential difference
• How does the charge flow in direct current?

  Always in the same direction
• Where can you find direct current (DC)?

  In cells and batteries
• What devices are used to obtain potential difference time graphs?

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

  • Direction constantly swaps
  • Produced by alternating voltage
  • Fluctuates between positive and negative
  • UK mains supply is AC at 50 Hz, ~240 volts
• What are the characteristics of direct current (DC)?

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

  • Display potential difference time graphs
  • Show fluctuations in voltage and current