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Questions and Answers
What is the definition of refraction of light?
What is the definition of refraction of light?
Refraction of light is the bending of light as it passes from one transparent medium to another.
Light always travels in a straight line.
Light always travels in a straight line.
False (B)
What is the speed of light in a vacuum?
What is the speed of light in a vacuum?
What is the name given to the angle between the incident ray and the normal?
What is the name given to the angle between the incident ray and the normal?
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What is the name given to the angle between the reflected ray and the normal?
What is the name given to the angle between the reflected ray and the normal?
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Which of the following statements is TRUE about the laws of reflection?
Which of the following statements is TRUE about the laws of reflection?
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Which of the following is an example of refraction of light?
Which of the following is an example of refraction of light?
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Which of these materials will slow down the light the most?
Which of these materials will slow down the light the most?
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What is the ratio of the speed of light in a vacuum to the speed of light in a medium called?
What is the ratio of the speed of light in a vacuum to the speed of light in a medium called?
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What is the primary reason why a swimming pool appears shallower than it actually is?
What is the primary reason why a swimming pool appears shallower than it actually is?
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A lens uses reflection to form an image.
A lens uses reflection to form an image.
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Which of the following does NOT use the principle of refraction?
Which of the following does NOT use the principle of refraction?
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Study Notes
Unit 6: Light - Week 21
- Topic: Reflection and Refraction
Learning Objectives
- Students will be able to describe how light reflects from a plane mirror.
- Students will understand the laws of reflection.
- Students will be able to draw ray diagrams to show light reflection.
- Students will understand refraction of light.
Nature of Light
- Light is a form of energy that allows us to see.
- Light travels in straight lines.
- Light travels at a very high speed (3.0 x 108 ms-1) in a vacuum.
- Luminous sources emit light, such as the sun, stars, candles, and lamps.
Reflection of Light
- We see reflections in mirrors.
- Reflections in a plane mirror are upright, the same size, and same color as the object.
- Moving closer to a mirror causes the image to move closer. Moving away causes the image to move away.
- Mirror images are virtual because there is nothing behind the mirror.
- Images projected onto a screen are real images.
- A mirror image is laterally inverted.
Reflection of Light (1) & (2)
- Reflection of Light (1): Shows the incoming ray, the reflected ray, and the normal to the mirror surface.
- Reflection of Light (2): Demonstrates and defines the angle of incidence (i) and angle of reflection (r). The angle of incidence always equals the angle of reflection.
Types of Reflection
- Regular Reflection: Parallel incident rays reflect as parallel rays, as seen in a plane mirror, producing a clear image.
- Diffuse Reflection: Incident rays reflect in different directions. This is how we see most surfaces.
Laws of Reflection
- Law 1: The angle of incidence (i) is equal to the angle of reflection (r).
- Law 2: The incident ray, reflected ray, and the normal to the surface all lie in the same plane.
Measuring Angles of Incidence and Reflection
- Using a protractor, measure the angles of incidence and reflection.
Making Measurements
- Techniques for precisely measuring angles of incidence and reflection using a protractor and a ray diagram.
Refraction of Light
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A pencil appears bent or broken when partially submerged in water due to refraction.
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Refraction occurs when light traveling from one transparent medium to another, such as air to water, changes direction.
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The change in direction occurs at the boundary between the two media.
Refraction
- Angle of incidence is the angle between the incident ray and the normal to the surface.
- Angle of refraction is the angle between the refracted ray and the normal to the surface.
Refraction (From air into water/glass)
- Light bends towards the normal when traveling from a less dense to a denser medium (e.g., air to water or air to glass).
Refraction (From water/glass into air)
- Light bends away from the normal when traveling from a denser to a less dense medium (e.g., water to air or glass to air).
Why Does Refraction Happen?
- The speed of light changes when it travels through different materials. Denser materials make light slow down.
- The ratio of the speed of light in a vacuum to the speed of light in a medium is the refractive index.
Applications of Refraction
- Lenses use refraction to form images.
- Eyeglasses (spectacles) for vision correction rely on the principles of refraction.
- Refraction is in peepholes, cameras, movie projectors, and telescopes.
Application of Refraction
- Pools look shallower due to the refraction of light.
- A spoon submerged in water appears bent.
- Refraction is how we perceive objects in different media.
Speed of Light and Refraction
- Light's speed changes when passing through different mediums.
- This speed change relates to the medium's density.
- The refractive index quantifies this relationship.
Applications of Refraction
- Lenses use refraction to form images.
- Eyeglasses correct vision problems.
- Refraction is used in peepholes, cameras, and telescopes.
Concept Check Questions
- Included questions about reflection and refraction. Answers are not provided as that would require a separate document.
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Description
Test your knowledge on the concepts of light refraction and reflection. This quiz covers definitions, laws of reflection, and the behavior of light in different mediums. Challenge yourself with various questions about angles, materials, and optical phenomena.
