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An image in a convex lens is upright and magnified 3 times. If the focal length of the ...

An image in a convex lens is upright and magnified 3 times. If the focal length of the lens is 15 cm, what is the object distance?
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  • A 10 cm
  • B 25 cm
  • C 16 cm
  • D 14 cm
Correct Answer: Option A
Explanation:
m = v/u = -3
v = -3u
f = 15cm1/v + 1/U = 1/f1/-3U + 1/u = 1/152/3u = 1/15
3U = 15 x 2
U = 30/3
= 10 cm

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