Light - Reflection & Refraction
This practical lesson covers:
- How to determine the refractive index of a glass block
Investigating the refractive index of a glass block Aim: To investigate the reflection of light by different types of surface and the refraction of light by different substances. |
Background information: When light travels from one material to another, it refracts. The greater the refractive index of a material, the more it refracts. In this practical, you will investigate the relationship between the angle of incidence and angle of refraction. You will then use measurements of these angles to calculate the refractive index of the glass block. |
Variables:
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The angle of incidence is ...
the angle between the normal and the boundary
the angle between the incident ray and the boundary
the angle between the incident ray and the normal
the angle between the refracted ray and the incident ray
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A students shines light at a glass block with an angle of incidence of 30o. The student measures the angle of refraction. The angle of refraction should be...
bigger than the angle of incidence
smaller than the angle of incidence
it is impossible to say
equal to the angle of incidence
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When light travels from a less optically dense medium such as air into a more optically dense medium such as glass, the speed of light as it crosses the boundary.
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Why does the student use a ray box instead of a torch?
the ray box provides a narrow beam of light which makes it more accurate to measure the angles of incidence and refraction
the torch isn't bright enough
a torch would run out of batteries
the torch light isn't able to pass through the glass block
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