Light Beam and Lenses - Physics Light
3211
Arnab De
11/01/2020
Rays of light
The straight line or path between two specific points in a light medium by which light travel is known as a light ray. Light rays a denoted by an arrow line that sets the direction of light. It is a vector quantity.
The set of light rays is known as a light beam. Three types of the light beam are possible
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Parallel Light Beam: If each and every light rays in a light beam are parallel to each other then it is known as a parallel light beam. When a light source situated at a long distance then the light beams came from that source is known as a parallel beam. E.g. sunlight.
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Convergent Light Beam: If light rays of a light beam coming from different directions and meet a point, then such light beam known as a convergent beam.
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Divergent Light Beam: If light rays of a light beam coming from a single point and travel in a different direction, then such light beam known as a divergent beam of rays.
Lens
Surround by two opposite surfaces, either both curved or one curve and another plane, a piece of transparent material (such as glass) and the homogeneous medium is known as a lens. Lenses are boldly categorised in two types
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Convex Lens or converging Lens: If a parallel light beam receives by one side of the lens and releases a convergent light beam from another side of the lens then that lens is known as a convex lens. In these types of lenses, the middle portion is thicker than the outer side.
E.g : Looking Glass
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Concave Lens or Diverging Lens: If a parallel light beam receives by one side of the lens and releases a divergent light beam from another side of the lens then that lens is known as a concave lens. In these types of lenses, the middle portion is thinner than the outer side.