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Questions
If focal length of a convex lens is 20 cm at what is the power of the lens?
The focal length of a convex lens is 20 cm. What is its power?
If a convex lens focal length is 20 c.m at what is the power of the lens?
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Solution
To solve `1/0.2`, you need to remove the decimal from the denominator.
Step 1: Multiply both the numerator (top) and the denominator (bottom) by 10 to shift the decimal point one place to the right.
`P = (1 × 10)/(0.2 × 10)`
Step 2: Simplify the fraction `P = 10/2`
Step 3: Divide 10 by 2. P = 5
So, the final power of the lens is 5 D.
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