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12 Cards in this Set
- Front
- Back
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Define Refraction
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Refraction is the bending of light rays at the boundary of another medium.
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What happens during refraction?
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Light rays bend toward the normal when entering a more optically dense medium, and bend away from the normal upon entering a less optically dense medium.
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Define the Absolute refractive index.
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This is the ratio between the velocity of light in air to the velocity of light in another medium.
V(air)/V(medium) = n (absolute refractive index). |
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State Snell's Law
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The ratio of the sine of the angle of incidence to the sine of the angle of refraction is constant for a particular material. This constant is the absolute refractive index of the material.
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What is the reciprocal law?
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The refractive index of light going from a material to air is the inverse of the index of light going from air to that medium.
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What does refraction cause for the observer?
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Refraction in a more optically dense medium like from air to water causes objects in the more optically dense medium to look closer than they actually are.
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Explain Total Internal Reflection.
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There comes a point at which r (angle of refraction) = 90. The ANGLE OF INCIDENCE THAT PRODUCES THIS is called the CRITICAL ANGLE (0c). If the angle of incidence is increased, then the ray of light is entirely reflected off the boundary of the two mediums.
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Where does light always bend in lenses?
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Toward the thickest part of the lens. It bends towards the normal entering, and away when leaving, but the net bend is toward the thickest part of the lens.
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What is the Dioptre?
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The dioptre (D) defines the optical power of a lens. It is equal to the reciprocal of the focal length of the lens.
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What type of images do concave lenses always produce?
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Virtual, diminished, upright, between F and the lens.
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Will an image produced in a convex lens be smaller or larger if the object is between 2f and f?
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It will be larger
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When do convex lenses form virtual images?
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When the object is placed between f and the lens.
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