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A concave lens of focal length 25 cm and...

A concave lens of focal length 25 cm and a convex lens of focal length 20 cm are placed in contact with eachother. What is the power of this combination ? Also, calculate focal length of the combination.

A

`+ 1D`

B

` + 9 D`

C

` - 1D`

D

`- 9 D`

Text Solution

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The correct Answer is:
B
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