ac/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 happens to the charge flow in an AC circuit?

  It constantly swaps back and forth
• 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 electricity?

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

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

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

  Both values are correct for exams
• What is direct current (DC) produced by?

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

  It flows in the same direction
• Where do we commonly find direct current (DC)?

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

  Oscilloscopes
• What are the key characteristics of alternating current (AC) and direct current (DC)?

  • AC:
  • Direction constantly swaps
  • Found in mains electricity
  • Voltage fluctuates between positive and negative
  • DC:
  • Flows in one direction
  • Found in batteries and cells
  • Voltage is constant
• What are the voltage and frequency specifications for UK mains electricity?

  • Voltage: 240 volts (or 230 volts)
  • Frequency: 50 hertz