f the power of the hand lens is +5D , what should be the distance between hand lens and book to read it properly?A.0.4 mB.0.2 mC.0.3 mD.0.5 m
Question
f the power of the hand lens is +5D , what should be the distance between hand lens and book to read it properly?A.0.4 mB.0.2 mC.0.3 mD.0.5 m
Solution
The power of a lens is given by the formula P = 1/f, where P is the power and f is the focal length. The power is given in diopters (D) and the focal length is given in meters (m).
Given that the power of the hand lens is +5D, we can rearrange the formula to solve for the focal length: f = 1/P.
Substituting the given power into the formula gives: f = 1/5 = 0.2 m.
Therefore, the distance between the hand lens and the book to read it properly should be 0.2 m. So, the correct answer is B.0.2 m.
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