A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?
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p = +1.5 D$\text{f}=\frac{100}{\text{p}} \ \text{cm}=\frac{100}{1.5}$
$=\frac{1000}{15}=+66.67 \ \text{cm}=+0.67 \ \text{m}$
As the focal length is +ve, it is convex lens. Hence, it is a converging lens.
$=\frac{1000}{15}=+66.67 \ \text{cm}=+0.67 \ \text{m}$
As the focal length is +ve, it is convex lens. Hence, it is a converging lens.
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