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A lens forms an image of an object placed at twice its focal length. The image is:
AAt F on the other side, diminished, real
BAt 2F on the other side, same size, inverted, real
CAt infinity, magnified, real
DVirtual, behind the lens
Answer & Solution
Correct answer: B. At 2F on the other side, same size, inverted, real
1. For a convex lens with u = -2f, applying the lens formula gives v = +2f.
2. The magnification m = v/u = -1, meaning image is same size and inverted.
3. Hence the image is at 2F, same size, real and inverted.
_Source: NCERT Class 10 Science, Ch 9 "Light Reflection and Refraction", §9.4.4_
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