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Question
Write the formula for a lens connecting image distance (v), object distance (u) and the focal length (f). How does the lens formula differ from the mirror formula?
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Solution
Lens formula is:
`1/v-1/u=1/f`
Now, the mirror formula is given by:
`1/v+1/u=1/f`
In both the formulas,
u = Object distance
v = Image distance
f = Focal length
In the mirror formula, a positive sign is present between the reciprocals of the image distance and object distance.
In lens formula, a negative sign is present between the reciprocals of image distance and object distance.
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