Ray diagram for a diverging lens

Ray diagram for a diverging lens - An example We can use...

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Ray diagram for a diverging lens Consider now the ray diagram for a diverging lens. Diverging lenses come in a few different shapes, but all diverging lens are fatter on the edge than they are in the center. A good example of a diverging lens is a bi-concave lens, as shown in the diagram. The object in this case is beyond the focal point, and, as usual, the place where the refracted rays appear to diverge from is the location of the image. A diverging lens always gives a virtual image, because the refracted rays have to be extended back to meet. Note that a diverging lens will refract parallel rays so that they diverge from each other, while a converging lens refracts parallel rays toward each other.
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Unformatted text preview: An example We can use the ray diagram above to do an example. If the focal length of the diverging lens is -12.0 cm (f is always negative for a diverging lens), and the object is 22.0 cm from the lens and 5.0 cm tall, where is the image and how tall is it? Working out the image distance using the lens equation gives: This can be rearranged to: The negative sign signifies that the image is virtual, and on the same side of the lens as the object. This is consistent with the ray diagram. The magnification of the lens for this object distance is: So the image has a height of 5 x 0.35 = 1.75 cm....
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This note was uploaded on 11/22/2011 for the course PHY PHY2053 taught by Professor Davidjudd during the Fall '10 term at Broward College.

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