To verify the laws of refraction by using a glass slab.

 

Abstract

This experiment aims to verify the laws of refraction (Snell's laws) using a glass slab. By observing and measuring the angles of incidence and refraction, students can confirm the relationship between incident and refracted angles.

Introduction

Refraction is the bending of light as it passes from one medium to another. Snell's laws describe the relationship between the angles of incidence and refraction and the refractive indices of the two media involved. This experiment demonstrates these laws using a glass slab.

Procedure

1. Set up a glass slab on a flat surface.
2. Place a light source and a protractor near the glass slab.
3. Direct a beam of light towards the glass slab at various angles of incidence.
4. Measure the angles of incidence and refraction using the protractor.
5. Repeat the experiment for different angles of incidence.

Abstract

This experiment aims to verify the laws of refraction (Snell's laws) using a glass slab. By observing and measuring the angles of incidence and refraction, students can confirm the relationship between incident and refracted angles.

Introduction

Refraction is the bending of light as it passes from one medium to another. Snell's laws describe the relationship between the angles of incidence and refraction and the refractive indices of the two media involved. This experiment demonstrates these laws using a glass slab.

Procedure

1. Set up a glass slab on a flat surface.
2. Place a light source and a protractor near the glass slab.
3. Direct a beam of light towards the glass slab at various angles of incidence.
4. Measure the angles of incidence and refraction using the protractor.
5. Repeat the experiment for different angles of incidence.

Observations and Calculations

1. Set up a glass slab on a flat surface.

   Observation: The glass slab is placed horizontally on the table.

   Calculation: No calculation required for this step.

2. Place a light source and a protractor near the glass slab.

   Observation: A light source (such as a laser or flashlight) is placed near one end of the glass slab. A protractor is placed adjacent to the glass slab for measuring angles.

   Calculation: No calculation required for this step.

3. Direct a beam of light towards the glass slab at various angles of incidence.

   Observation: When the light beam passes from air into the glass slab, it bends towards the normal.

   Calculation: No calculation required for this step.

4. Measure the angles of incidence and refraction using the protractor.

   Observation: The angle of incidence (\( \theta_1 \)) is measured between the incident ray and the normal. The angle of refraction (\( \theta_2 \)) is measured between the refracted ray and the normal.

   Calculation: No calculation required during the observation. Calculation of the refractive index can be done later using Snell's law.

5. Repeat the experiment for different angles of incidence.

   Observation: The experiment is repeated with the light beam incident at various angles, and corresponding angles of refraction are measured.

   Calculation: No calculation required during the observation. Refractive indices can be calculated using Snell's law after obtaining angle measurements.

Short Questions with Answers

1. What is refraction?
   Answer: The bending of light as it passes from one medium to another.
2. What are Snell's laws?
   Answer: Laws describing the relationship between the angles of incidence and refraction and the refractive indices of the two media involved.
3. What is the refractive index of a medium?
   Answer: A measure of how much light bends when entering that medium from another.
4. What is the relationship between the angle of incidence and the angle of refraction?
   Answer: They are related by Snell's laws, which state that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant.
5. How does the refractive index of a medium affect the angle of refraction?
   Answer: A higher refractive index leads to a greater angle of refraction.
6. What is the refractive index of air?
   Answer: Approximately 1.0003.
7. What is the refractive index of vacuum?
   Answer: Exactly 1.0000.
8. What factors affect the magnitude of refraction?
   Answer: The angle of incidence and the refractive indices of the two media involved.
9. How does light behave when it passes from a rarer medium to a denser one?
   Answer: It bends towards the normal.
10. How does light behave when it passes from a denser medium to a rarer one?
    Answer: It bends away from the normal.
11. What is the normal in the context of refraction?
    Answer: An imaginary line perpendicular to the surface separating the two media.
12. What is the angle of deviation?
    Answer: The angle between the incident ray and the emergent ray after passing through a refracting surface.
13. What is total internal reflection?
    Answer: The phenomenon where all the light incident on a boundary is reflected back into the original medium due to a critical angle being exceeded.
14. What is the critical angle?
    Answer: The angle of incidence that produces an angle of refraction of 90 degrees.
15. What is the difference between reflection and refraction?
    Answer: Reflection involves the bouncing back of light rays from a surface, while refraction involves the bending of light rays as they pass from one medium to another.
16. What is the refractive index of water?
    Answer: Approximately 1.333.
17. What is the speed of light in a vacuum?
    Answer: Approximately 299,792,458 meters per second.
18. What are some practical applications of refraction?
    Answer: Lenses, prisms, and optical fibers rely on the principles of refraction.
19. How does the wavelength of light change when it enters a denser medium?
    Answer: It decreases.
20. What happens to the speed of light when it enters a denser medium?
    Answer: It decreases.

Multiple Choice Questions with Answers

1. What is the phenomenon observed when light bends as it passes from one medium to another?
   1. Reflection
   2. Refraction
   3. Diffraction
   4. Interference
   Answer: B. Refraction
2. Which of the following laws describes the relationship between the angles of incidence and refraction?
   1. Newton's law
   2. Snell's law
   3. Fermat's principle
   4. Gauss's law
   Answer: B. Snell's law
3. What happens to the speed of light when it enters a denser medium?
   1. It increases
   2. It decreases
   3. It remains the same
   4. It becomes zero
   Answer: B. It decreases
4. At what angle of incidence does total internal reflection occur?
   1. 45 degrees
   2. 60 degrees
   3. 90 degrees
   4. Depends on the refractive index
   Answer: C. 90 degrees
5. What is the refractive index of a medium with respect to vacuum called?
   1. Absorptive index
   2. Relative index
   3. Absolute index
   4. Refractivity index
   Answer: C. Absolute index