Investigating Light

• What equipment is used in the investigation of reflection and refraction?

  • Ray box
  • Lens
  • Slit
• What does a ray box produce?

  A novel ray of light
• Why should the ray box be switched off when not in use?

  It gets hot and can be dangerous
• What is a safer alternative to using a ray box for this practical?

  Using a laser
• What should you draw on the A3 paper to start the experiment?

  A straight line down the center
• What is the purpose of the protractor in the experiment?

  To draw a line at right angles
• What do we label the line drawn at right angles?

  The normal
• Where should the glass block be placed in relation to the normal?

  Near the center of the block
• What should be done before directing the ray of light at the block?

  Turn out all the lights in the room
• What is the incident ray?

  The ray hitting the block at the normal
• What is the angle of incidence?

  The angle between the incident ray and the normal
• What happens when the angle of incidence is adjusted?

  A ray reflects from the surface of the block
• What do we call the ray leaving the block?

  The transmitted ray
• How do we mark the paths of the rays?

  With crosses for incident and reflected rays
• What should be done after marking the paths of the rays?

  Turn on the room lights
• What angles do we measure in the experiment?

  Angle of incidence, reflection, and refraction
• What is the angle of reflection?

  The angle between the normal and the reflected ray
• What is the angle of refraction?

  The angle between the normal and the transmitted ray
• What should you expect when using a different material like perspex?

  Different angle of refraction than glass
• What remains the same for both glass and perspex?

  The angles of incidence and reflection
• What is the relationship between angle of refraction and material?

  It varies with different materials
• What should you remember about the required practical?

  • It involves investigating reflection and refraction
  • Use a ray box, lens, and slit
  • Measure angles of incidence, reflection, and refraction
• What are the steps to conduct the light investigation?

  1. Draw a straight line and normal
  2. Place glass block and direct ray of light
  3. Mark paths of incident, reflected, and transmitted rays
  4. Measure angles using a protractor
  5. Repeat with different materials