Potential difference, Current, Resistance

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

  v = ir
• What does the equation v = ir represent in electrical circuits?

  It represents potential difference or voltage equals current times resistance.
• If a circuit has a current of 4 amps and a resistance of 2 ohms, what is the voltage?

  The voltage is 8 volts.
• How do you calculate resistance if you have a voltage of 24 volts and a current of 8 amps?

  You calculate resistance using r = v / i, which gives 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 indicating a proportional relationship.
• What does a steeper line on a current versus potential difference graph indicate?

  It indicates a smaller resistance.
• What effect does increasing temperature have on resistance in a circuit?

  Increasing temperature generally increases resistance.
• What is the behavior of filament lamps as current increases?

  The resistance increases, causing the curve to become less steep.
• Why do diodes only allow current to flow in one direction?

  They have a high resistance in the reverse direction, preventing current flow.
• What are the key characteristics of current versus potential difference graphs for different components?

  • Wires/Resistors: Straight line, constant resistance.
  • Filament Lamps: Curved line, increasing resistance with current.
  • Diodes: Current flows only in one direction, high reverse resistance.