Filament Lamps

• What type of energy does a filament lamp convert into light?

  Electrical energy
• What happens to the filament wire in a bulb when current flows through it?

  It heats up and glows
• What is the shape of the IV graph for a filament lamp?

  Curved
• What do IV graphs show us about a component?

  The relationship between current and potential difference
• Where is current plotted on the IV graph?

  On the y-axis
• Where is potential difference plotted on the IV graph?

  On the x-axis
• What does the curved shape of the IV graph for a filament lamp indicate?

  It indicates that the filament lamp is a non-ohmic conductor
• How do ohmic conductors differ from non-ohmic conductors in terms of IV graphs?

  Ohmic conductors have straight IV graphs, while non-ohmic conductors have curved IV graphs
• What happens to the resistance of a filament lamp as the current increases?

  The resistance increases
• What does the gradient of an IV graph represent?

  The resistance of the component
• How is the gradient calculated on an IV graph?

  By dividing current by potential difference
• What does a steeper IV graph indicate about resistance?

  A steeper IV graph indicates lower resistance
• What does a nearly horizontal IV graph indicate about the filament lamp's resistance at high currents?

  It indicates very high resistance
• Why does the resistance of the lamp change with increasing current?

  Because larger currents cause the temperature of the filament to increase
• What is the primary reason the lamp works?

  Heat building up in the filament
• What happens to the temperature of the filament as the current increases?

  The temperature increases
• What are the key characteristics of the IV graph for a filament lamp?

  • Curved shape
  • Steeper in the middle for low potential differences
  • Flattens out at high potential differences
  • Indicates non-ohmic behavior
• What are the differences between ohmic and non-ohmic conductors?

  • Ohmic conductors:
  • Constant resistance
  • Straight IV graphs
  • Non-ohmic conductors:
  • Variable resistance
  • Curved IV graphs
• What factors affect the resistance of a filament lamp?

  • Current level
  • Temperature of the filament
  • Higher current leads to higher temperature and resistance
• What resources are available for GCSE Physics revision?

  • Interactive quizzes
  • Easy-to-follow videos
  • AI tutor support