Question

a convex lens has focal length 20 CM calculate at which distance from the lens should be the object be placed so that it from an image at 40 cm on the other side of the lens state the nature of the image formed

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Answer 1

Answer:

f = 20 cm

v = 40 cm

$\frac{1}{f} = \frac{1}{v} - \frac{1}{u}$

$\frac{1}{20} = \frac{1}{40} - \frac{1}{u}$