Resistance of a Filament Lamp

• What should you be able to describe by the end of the video?

  The current potential difference graph for a filament lamp
• What is the relationship between current and potential difference in a resistor?

  Current is directly proportional to potential difference
• What type of conductors are resistors that follow Ohm's law?

  Ohmic conductors
• Under what condition does the resistance of a resistor remain constant?

  If the temperature does not change
• What happens to the resistance of a filament lamp as it gets hotter?

  The resistance increases
• How does the current through a filament lamp compare to that through a resistor?

  Current is not directly proportional to potential difference
• What is the main reason filament lamps are being phased out?

  They are not energy efficient
• What does the term 'filament' refer to in a filament lamp?

  A very fine wire that glows when heated
• What happens to the atoms in the filament when the temperature increases?

  They vibrate more
• Why is more energy needed to push current through a hot filament lamp?

  Electrons collide more with vibrating atoms
• What is a key feature of the graph obtained from a filament lamp experiment?

  The current does not increase as much at high potential differences
• What does it mean if a filament lamp is not an ohmic conductor?

  Its resistance changes with temperature
• What are the key points about the current potential difference graph for a filament lamp?

  • Current is not directly proportional to potential difference
  • Resistance increases with temperature
  • The graph shape is non-linear
• Where can you find questions on the resistance of a filament lamp?

  In the vision workbook
• What should you be able to explain about the shape of the current potential difference graph for a filament lamp?

  Why the graph is non-linear