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An object is x times, the focal length ofa concave mirror away from the principal focus. Show that the image will be (1)/(nx) times the focal lehght of mirror away from principal focus, where n is : |
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Answer» `(1)/(2)` `therefore U = - f - fx = - (X + 1) f` `(1)/(f) = (1)/(u) + (1)/(v)` `therefore (1)/(v) = (1)/(f) - (1)/(u) = (1)/(-f) + (1)/((x+1)f)` `=(-x-1+1)/((x+1)f)=-(x)/((x+1)f)` `v=-((x+1)f)/(x)=-(1+(1)/(x))f=-(1+(1)/(x))f.` Distance of image from Principa focus is `= (1)/(x) xx f = (1)/(x)` times the focal lenght `therefore n = 1` |
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