Refraction

• Why is a slit used in the ray box?

  To create a straight ray of light
• What type of block is primarily used in the practical?

  A rectangular glass or perspex block
• Why is it best to conduct the experiment in a dark room?

  To see the light rays more clearly
• What should you do after placing the perspex block on the paper?

  Draw around it with a sharp pencil
• What is the angle of incidence?

  The angle between the ray and the normal
• What does the normal line represent?

  A line at 90 degrees to the surface
• What happens to light when it enters a new medium?

  It changes direction and speed
• What is the relationship between the angle of incidence and the angle of reflection?

  They are always equal
• What is the angle of refraction?

  The angle at which light exits the block
• What does a higher refractive index indicate?

  Light bends more as it enters the medium
• What is total internal reflection (TIR)?

  Light reflects completely within a medium
• What is the critical angle?

  The angle of incidence for TIR to occur
• What conditions are needed for TIR to happen?

  Angle of incidence must exceed critical angle
• What must be true about the mediums for TIR to occur?

  Light must move from a denser to a less dense medium
• How does the semicircular block demonstrate TIR?

  It shows light reflecting when angle exceeds critical angle
• What happens to the angle of refraction as the angle of incidence increases?

  It gets larger until TIR occurs
• What is the significance of the angle of incidence being 43 degrees?

  It is the critical angle for TIR
• Why did TIR not occur when the semicircular block was positioned differently?

  Light was entering from air into glass
• What happens when the angle of incidence exceeds the critical angle?

  Only reflection occurs, no refraction
• What is the purpose of drawing the normal line?

  To measure angles accurately
• How does the angle of incidence relate to the normal line?

  It is measured from the normal line
• What should you do after measuring angles of incidence and refraction?

  Plot a graph of sine I against sine R
• How can you compare refractive indices of different materials?

  By repeating the experiment with different blocks
• What does a straight line graph of sine I against sine R indicate?

  It shows a consistent refractive index
• What is the significance of the term "optically dense medium"?

  It has a higher refractive index
• Why is it important to keep the block in the same position?

  To ensure consistent measurements
• How does the angle of incidence affect the behavior of light in the experiment?

  It determines whether light refracts or reflects
• What is the role of the protractor in the experiment?

  To measure angles of incidence and refraction
• What happens to light when it exits the glass block?

  It refracts and may reflect partially
• What is the significance of measuring multiple angles?

  To improve accuracy of refractive index
• How does the experiment demonstrate the principles of refraction?

  By showing light bending at different angles
• What is the relationship between the angle of incidence and the angle of refraction?

  They change based on the medium's refractive index
• What is the purpose of the experiment on refraction?

  To understand how light behaves in different mediums
• How does the experiment relate to real-world applications?

  It explains phenomena like fiber optics
• What can be concluded from the results of the experiment?

  Light behavior can be predicted using refractive indices
• Why is it important to understand refraction in physics?

  It helps explain various optical phenomena
• What is the main focus of the practical demonstration?

  Refraction of light through different mediums
• How does the experiment help in understanding light behavior?

  It illustrates how light bends and reflects
• What is the significance of the angle of incidence being greater than the critical angle?

  It leads to total internal reflection
• What happens to light rays at the boundary of two mediums?

  They can reflect, refract, or both