v=ir

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

  v = ir
• What does the equation v = ir represent?

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

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

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

  Less resistance in the circuit
• What effect does increasing temperature have on resistance?

  Resistance increases
• How does the resistance of a filament lamp change with increasing current?

  Resistance increases as current increases
• What happens to current when the potential difference across a diode is negative?

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

  • Straight lines indicate constant resistance
  • Steeper lines indicate less resistance
  • Shallower lines indicate more resistance
• What are the effects of temperature on resistance in electrical components?

  • Higher temperature increases resistance
  • Lower temperature decreases resistance
  • Resistance changes affect current flow
• What are the differences between filament lamps and diodes?

  Filament Lamps:

  • Emit light when heated
  • Resistance increases with current

  
  

  Diodes:

  • Allow current in one direction only
  • High resistance in reverse direction