V = IR

• What is the equation that relates voltage, current, and resistance?

  v = ir
• What does the equation v = ir stand for?

  Potential difference (voltage) equals current times resistance
• If a circuit has a current of 4 amps and a resistance of 2 ohms, what is the voltage?

  8 volts
• How do you find the resistance if you have a 24 volt battery producing a current of 8 amps?

  By rearranging the equation to r = v / i and calculating
• What is the resistance when using a 24 volt battery with a current of 8 amps?

  3 ohms
• What happens to current when voltage increases while resistance remains constant?

  The current increases proportionally
• What does a graph of current against potential difference show when resistance is constant?

  It shows a straight line
• What does a steeper line on a current versus potential difference graph indicate?

  A smaller resistor is present
• What happens to resistance if the temperature increases?

  The resistance increases
• Why do filament lamps have a less steep curve as current increases?

  Because the heat increases resistance
• What is the function of a diode in a circuit?

  It allows current to flow in one direction only
• What happens to current when the potential difference is negative in a diode?

  No current flows
• What are the key characteristics of current versus potential difference graphs for resistors?

  • Straight lines indicate constant resistance
  • Steeper lines indicate smaller resistors
  • Less steep lines indicate larger resistors
• What are the effects of temperature on resistance in electrical components?

  • Increased temperature leads to increased resistance
  • Higher currents can cause wires to heat up
  • Resistance behavior may vary in practice
• What are the differences between filament lamps and diodes in terms of current flow?

  • Filament lamps: Resistance increases with current, leading to less current flow at higher voltages
  • Diodes: Allow current flow only in one direction, blocking reverse current