Refraction

• What is the main focus of Core Practical 3?

  Investigate refraction in glass blocks
• What equipment is needed for the refraction investigation?

  • Ray box and single slit grating
  • Glass block
  • Paper
  • Pen/pencil
  • Ruler
  • Protractor
• How should the equipment be set up for the experiment?

  In a darkened room as shown in the diagram
• What should you do after placing the glass block on the paper?

  Draw around it to mark its position
• What is the purpose of drawing a normal line?

  To indicate the angle of incidence reference
• What angles should be used as guides for incidence?

  20º, 40º, and 60º
• What should you do after directing light along the incidence lines?

  Mark where the light exits the block
• How should you connect the points of incidence and exit?

  Draw lines connecting them with a ruler
• What should be ensured at each exit point of light?

  A normal line should be drawn
• How should angles of incidence and refraction be measured?

  Relative to the normal line
• What happens to the angle of refraction when light enters glass from air?

  It is smaller than the angle of incidence
• What happens to the angle of refraction when light exits glass into air?

  It is greater than the angle of incidence
• What should be plotted on the graph after the experiment?

  • Angle of refraction against angle of incidence
  • One line for glass into air
  • Another line for air into glass
• What safety precautions should be taken during the experiment?

  • Do not touch the ray box when in use
  • Be cautious of trip hazards in darkened rooms
• Why should the ray box not be touched during the experiment?

  It gets hot and can cause burns
• What is a potential hazard in a darkened room?

  Trip hazards that are less visible