A virtual image twice as long as the object is formed by a convex lens when the object is 10 cm away from it. A real image twice as long as the object will be formed when it is placed at a distance…..from the length

Question

Dr. Abubacker · Accepted Answer

(b) $m = \frac{f}{f + u}$
Now ,$+ 2 = \frac{f}{f - 10}$
Or $2f - 20 = f\ $or$\ f = 20\ cm$
Again $- 2 = \frac{20}{20 + u}\ \ $or$\  - 40 - 2u = 20$
Or $- 2u = 20 + 40\ $or$\ \ u = - 30\ cm$

Q. A virtual image twice as long as the object is formed by a convex lens when the object is 10 cm away from it. A real image twice as long as the object will be formed when it is placed at a distance…..from the length

Explanation

Reviewed by Dr. Abubacker

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