6.2.5 Required Practical: Investigating Infrared Radiation

• What is one of the required practicals in the Year 11 GCSE Physics curriculum?

  Investigating infrared (IR) radiation
• What is the aim of the practical involving infrared radiation?

  To investigate how the amount of infrared radiation emitted or absorbed by an object varies with its surface
• What equipment is typically used in the infrared radiation practical?

  • Infrared (IR) Radiation Source (lamp or heater)
  • Thermometer or Thermocouple
  • IR Detector or Photodiode
  • Materials to Test (shiny metal, matte black paper, white paper)
  • Ruler
  • Clamp Stand
  • Thermal Imaging Camera (if available)
• How should the IR radiation source be positioned in the experiment?

  It should be positioned to emit radiation towards the test materials
• What should be done with the test materials before measuring infrared radiation?

  Cut pieces of different materials with different surface finishes and place them at the same distance from the IR source
• What is the purpose of measuring the baseline temperature in the experiment?

  To establish a reference point before the IR source is turned on
• What should be done after turning on the IR source?

  Record the temperature of each material after a fixed period
• Why is it important to repeat the experiment several times?

  To ensure accuracy and reliability of the results
• What are the expected results regarding surface properties in the infrared radiation experiment?

  • Matte black surfaces absorb and emit infrared radiation more effectively than shiny surfaces.
  • Shiny surfaces tend to reflect IR radiation rather than absorb it.
• What temperature changes might be observed in the experiment?

  Materials with higher emissivity, like matte black, show a greater temperature increase compared to those with lower emissivity, like shiny metal
• What should be included in the analysis of the infrared radiation experiment results?

  • Plot graphs showing temperature changes over time.
  • Analyze how IR intensity varies with different surfaces.
• What conclusion can be drawn if matte black paper has a higher temperature increase compared to shiny metal?

  It can be inferred that matte black paper has higher emissivity
• What safety consideration should be taken when working with infrared radiation?

  Avoid direct eye exposure to the IR source
• What should be done to handle heat sources safely during the experiment?

  Be cautious when handling any heating elements or lamps to avoid burns
• What aspects should be evaluated after conducting the infrared radiation experiment?

  • Check the accuracy of measurements.
  • Consider sources of error (e.g., variations in distance, ambient temperature).
  • Suggest improvements (e.g., using more precise equipment).
• How does understanding this practical help students in their exams?

  It helps them grasp how infrared radiation interacts with different materials