A lens forms an erect virtual image of an object. Using the sign convention and the relation $m=v/u$, what can be said about the magnification?
A$m$ is always negative for a virtual image
B$m$ is positive for an erect virtual image
C$m$ is zero because virtual images cannot be measured
D$m$ must be less than zero but greater than $-1$
Answer & Solution
Correct answer: B. $m$ is positive for an erect virtual image
For a lens, $m=h'/h=v/u$. The text states that for an erect and virtual image formed by either a convex or a concave lens, magnification is positive. Negative magnification corresponds to an inverted real image.
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