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Question
The power of convex lens of focal length 20 cm is ______.
Options
+5.0 D
0.20 D
-5.0 D
0.5 D
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Solution
The power of convex lens of focal length 20 cm is +5.0 D.
Explanation:
Given: Focal length = f = 20 cm = 0.2 m
Power of the lens = P = ?
P = `1/("f"("m"))`
= `1/0.2`
= 5 D
The power of the lens is 5 D.
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