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Two convex lenses of focal lengths f(1) ...

Two convex lenses of focal lengths `f_(1) and f_(2)` respectively are placed in contact with each other. Then what will be power of their equivalent lens?

Text Solution

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Powers of the two lenses are `P_(1) = (1)/(f_(1)) and P_(2) = (1)/(f_(2))`. As they are placed in contact, the power of the equivalent lens is,
`P = P_(1) + P_(2) = (1)/(f_(1)) + (1)/(f_(2))`
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