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Under what condition does a light ray not change its direction when refracting?
Under what condition does a light ray not change its direction when refracting?
What happens to the speed of light when it moves from a rarer medium to a denser medium?
What happens to the speed of light when it moves from a rarer medium to a denser medium?
Which of the following factors does NOT affect the refractive index of a medium?
Which of the following factors does NOT affect the refractive index of a medium?
In which scenario does the wavelength of light change during refraction?
In which scenario does the wavelength of light change during refraction?
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Which color of light travels the slowest in a medium?
Which color of light travels the slowest in a medium?
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What does the principle of reversibility of light state?
What does the principle of reversibility of light state?
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How does increasing temperature in a medium affect its refractive index?
How does increasing temperature in a medium affect its refractive index?
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What remains unchanged during the process of refraction of light?
What remains unchanged during the process of refraction of light?
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What happens to a light ray as it enters a glass block from air?
What happens to a light ray as it enters a glass block from air?
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What is the relationship between the angle of incidence and the angle of emergence in a rectangular glass block?
What is the relationship between the angle of incidence and the angle of emergence in a rectangular glass block?
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What is the lateral displacement of a light ray as it passes through a glass block?
What is the lateral displacement of a light ray as it passes through a glass block?
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What type of medium is a prism classified as?
What type of medium is a prism classified as?
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In terms of refraction, which equation relates the refractive indices and sine of the angles?
In terms of refraction, which equation relates the refractive indices and sine of the angles?
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What describes the path of a light ray after passing through a rectangular glass block?
What describes the path of a light ray after passing through a rectangular glass block?
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What can be concluded about the normal line in relation to the surfaces of a glass block?
What can be concluded about the normal line in relation to the surfaces of a glass block?
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What characteristic does a prism have concerning its geometry?
What characteristic does a prism have concerning its geometry?
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What is the term used for the angle between the two refracting surfaces of a prism?
What is the term used for the angle between the two refracting surfaces of a prism?
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What happens to a monochromatic ray of light when it strikes the face AB of a prism?
What happens to a monochromatic ray of light when it strikes the face AB of a prism?
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In the context of a prism, what is the emergent ray represented as?
In the context of a prism, what is the emergent ray represented as?
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Which of the following equations represents the relationship between the angle of incidence, angle of emergence, and angle of deviation?
Which of the following equations represents the relationship between the angle of incidence, angle of emergence, and angle of deviation?
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What does the angle of deviation (δ) depend on?
What does the angle of deviation (δ) depend on?
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How is the angle of incidence at face AC denoted?
How is the angle of incidence at face AC denoted?
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When viewed from a rarer medium, where does an object in a denser medium appear to be?
When viewed from a rarer medium, where does an object in a denser medium appear to be?
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What is the principal section of the prism?
What is the principal section of the prism?
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What occurs when light travels from a rarer medium to a denser medium?
What occurs when light travels from a rarer medium to a denser medium?
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What is the deviation of the ray when it travels from a denser medium to a rarer medium?
What is the deviation of the ray when it travels from a denser medium to a rarer medium?
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According to Snell's law, what remains constant for a given pair of media?
According to Snell's law, what remains constant for a given pair of media?
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What is the absolute refractive index of a transparent medium with respect to vacuum?
What is the absolute refractive index of a transparent medium with respect to vacuum?
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What happens to a ray of light incident normally on the surface separating two media?
What happens to a ray of light incident normally on the surface separating two media?
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What happens to the critical angle when the temperature of a medium increases?
What happens to the critical angle when the temperature of a medium increases?
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Which color of light has the lowest refractive index when passing through a medium?
Which color of light has the lowest refractive index when passing through a medium?
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What is the formula for the refractive index of medium 2 with respect to medium 1?
What is the formula for the refractive index of medium 2 with respect to medium 1?
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When light moves from a denser medium to a rarer one, which of the following statements is true?
When light moves from a denser medium to a rarer one, which of the following statements is true?
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Under what condition does total internal reflection occur?
Under what condition does total internal reflection occur?
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How does the brightness of an image formed by total internal reflection compare to that of a reflection from a plane mirror?
How does the brightness of an image formed by total internal reflection compare to that of a reflection from a plane mirror?
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How fast does light travel in vacuum?
How fast does light travel in vacuum?
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What is the relationship between critical angle and wavelength of light?
What is the relationship between critical angle and wavelength of light?
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What is the relationship between the angle of incidence and the angle of refraction when light travels from a denser medium to a rarer medium?
What is the relationship between the angle of incidence and the angle of refraction when light travels from a denser medium to a rarer medium?
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What happens to the apparent depth of an object when viewed in water compared to its real depth?
What happens to the apparent depth of an object when viewed in water compared to its real depth?
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What is the impact on light energy during total internal reflection?
What is the impact on light energy during total internal reflection?
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What is the critical angle?
What is the critical angle?
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What defines the refractive index of a medium with respect to glass?
What defines the refractive index of a medium with respect to glass?
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Which of the following best describes why we see the sun before it actually rises?
Which of the following best describes why we see the sun before it actually rises?
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What occurs at the boundary of a plane mirror when light is incident?
What occurs at the boundary of a plane mirror when light is incident?
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How is the shift between real depth and apparent depth calculated?
How is the shift between real depth and apparent depth calculated?
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In which scenario does a star appear to twinkle?
In which scenario does a star appear to twinkle?
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When the angle of incidence is equal to the critical angle, what happens to the light ray?
When the angle of incidence is equal to the critical angle, what happens to the light ray?
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What phenomenon occurs when a coin at the bottom of a vessel becomes visible after pouring water into it?
What phenomenon occurs when a coin at the bottom of a vessel becomes visible after pouring water into it?
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Study Notes
Refraction of Light
- Refraction is the change in direction of light as it passes from one transparent medium to another.
- This is a surface phenomenon.
- When light goes from a rarer medium to a denser medium, it bends towards the normal. The deviation is (i − r). (i= angle of incidence, r= angle of refraction)
- When light goes from a denser medium to a rarer medium, it bends away from the normal. The deviation is (r − i).
- A ray of light incident normally on a surface passes undeviated.
- Light bends because its speed changes.
Laws of Refraction
- The incident ray, refracted ray and the normal to the surface all lie in the same plane.
- The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for a given pair of media and for a given wavelength. This is Snell's Law. (sin i / sin r = constant = μ₂/μ₁) (μ=refractive index)
Speed of Light and Refractive Index
- Light travels fastest in a vacuum (c = 3 × 10⁸ m/s).
- The refractive index of medium 2 with respect to medium 1 (μ₂₁) is the ratio of the speed of light in medium 1 to the speed of light in medium 2 (v₁/v₂).
- The refractive index of a medium is always greater than 1.
Change in Speed, Direction and Wavelength of Light
- Light's speed changes during refraction.
- Light bends when passing between media with different densities
- Frequency of light does not change during refraction
- Wavelength changes due to the change in the speed of light
Factors affecting Refractive Index
- Optical density of the medium. A medium with a higher optical density has a greater refractive index.
- Temperature—higher temperatures increase the speed of light in a medium, reducing the refractive index.
- Colour/wavelength—the speed of different colours of light is different in a medium. Violet has a higher refractive index, while red has a lower refractive index.
Principle of Reversibility of the Path of Light
- The path of a light ray undergoing refraction is reversible.
Refraction through a Rectangular Glass Block
- Light bends towards the normal when passing from air to glass.
- Light bends away from the normal when passing from glass to air.
- The emergent ray is parallel to the incident ray, but not in the same line—there is a lateral displacement.
Prism
- A prism is a transparent medium with a triangular cross-section.
- The angle between the two refracting surfaces is the angle of prism.
- The intersection line is the refracting edge.
- Refraction of light through a prism causes deviation.
- Deviation depends on the angle of incidence, the refractive index of the prism, and the angle of the prism.
Total Internal Reflection
- Total internal reflection occurs when light going from a denser to a rarer medium, at an angle greater than the critical angle.
- The ray is completely reflected back into the denser medium.
Critical Angle and Refractive Index
- The critical angle is the incident angle in denser medium, where the refracted angle in the rarer medium is 90°.
- The critical angle depends on the refractive index. (sin ic = 1/μ₂)
Real Depth and Apparent Depth
- Real depth is the actual distance of an object from the surface.
- Apparent depth is the perceived distance of the object from the surface.
- When viewed through a medium (like water), the object appears closer to the surface than its actual position.
- (Apparent depth/Real depth = n₂)
Consequences of Refraction of Light
- Stars twinkle due to atmospheric refraction; starlight bends multiple times.
- The apparent position of stars differs.
- The Sun appears a few minutes before sunrise and after sunset due to atmospheric refraction.
Optical fibres
- Used for transmitting light (and consequently data) over long distances with relatively low signal loss.
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Description
This quiz covers the fundamental concepts of refraction of light, including the laws governing refraction and Snell's Law. It explores how light changes direction when passing through different media and the implications of refractive index on the speed of light. Test your understanding of these important principles in optics.