AQA GCSE FOUNDATION Physics: Investigating the Refraction of Light

Investigating the Refraction of Light

Objective:

To investigate the refraction of light through a glass block and determine the refractive index of the glass.

Materials:

• A glass block
• A ray box with a single slit
• A protractor
• A sheet of paper
• A pencil

Procedure:

1. Set up the Experiment:

   • Place the glass block on a sheet of paper and trace its outline with a pencil.
   • Use the ray box to shine a narrow beam of light onto the glass block.
   • Adjust the angle of incidence of the light beam.

2. Measure Angles:

   • Draw the normal line at the point where the light beam enters the glass block.
   • Measure the angle of incidence (i) between the incident ray and the normal.
   • Observe the path of the light beam as it passes through the glass block.
   • Draw the refracted ray and measure the angle of refraction (r) between the refracted ray and the normal.

3. Repeat Measurements:

   • Repeat steps 1 and 2 for at least five different angles of incidence.
   • Record your measurements in a table.

Data Table:

Analysis:

1. Calculate Refractive Index:

   • Use Snell's Law to calculate the refractive index (n) of the glass block for each angle of incidence:
   • n = sin i / sin r

2. Average Refractive Index:

   • Calculate the average refractive index from your measurements.

Discussion:

• Refraction of Light: Explain why light bends when it passes from air into glass.
• Snell's Law: Explain the relationship between the angle of incidence, angle of refraction, and the refractive index.
• Refractive Index: What does the refractive index of a material tell you about the speed of light in that material?
• Errors: Discuss any potential sources of error in your experiment and how they might affect your results.

Conclusion:

• State your conclusions based on your findings, including the refractive index of the glass block.

Further Investigation:

• Investigate how the refractive index of a material changes with the wavelength of light.
• Explore other applications of refraction, such as lenses and prisms.

Understanding Light Bending at Boundaries:

Light travels at different speeds in different mediums. When light passes from one medium to another, its speed changes, causing the direction of the light beam to bend. This phenomenon is called refraction. The refractive index of a material is a measure of how much light bends when it enters the material. A higher refractive index means a greater bending of light.

This experiment allows you to observe and quantify the bending of light at the boundary between air and glass, providing a hands-on understanding of the principles of refraction and Snell's Law.