Refraction

• What is the first step in the practical procedure?

  Draw around the block on paper
• Why do you draw a line normal to one of the sides?

  To establish a reference for angles
• How many guide lines should be drawn for incident rays?

  Three guide lines
• What should you do after placing the block on the page?

  Shine the ray light along a guide line
• What should you mark on the paper after shining the ray light?

  Incoming and outgoing rays with crosses
• What should you do after turning the lights on?

  Measure angles of reflection and refraction
• What tool is used to draw the normal line?

  A set square or protractor
• What is the purpose of drawing guidelines for incident rays?

  To shine the ray at exact angles
• What precautions should be taken when using the ray box?

  Don't touch metal parts; switch off when not in use
• What conditions are needed for the experiment?

  Low lighting for visibility of rays
• What safety precaution should be taken in a darkened lab?

  Move bags and equipment out of the way
• What two angles should be measured after marking the light rays?

  Angle of reflection and angle of refraction
• How should angles be measured?

  Using a protractor
• What is the angle of incidence?

  Angle between the incident ray and the normal
• What is the angle of reflection?

  Angle between the reflected ray and the normal
• What is the normal in this context?

  Line perpendicular to the surface of the mirror
• How do you draw the refracted ray?

  Connect entry and exit points with a straight line
• What is expected about the angle of incidence and angle of reflection?

  They should be the same
• What is expected about the angle of refraction for different materials?

  It should differ depending on refractive index
• How should the angle of refraction compare with the angle of incidence for light passing from air into glass?

  Angle of refraction should be less than angle of incidence
• How should the angle of refraction compare with the angle of incidence for light passing from glass into air?

  Angle of refraction should be greater than angle of incidence
• Explain the results for refraction between air and glass.

  Glass is denser, causing waves to bend