Question

Which of the following statements is incorrect?
(A) For a convex mirror, magnification is always negative.
(B) For all virtual images formed by a mirror, magnification is positive.
(C) For a concave lens, magnification is always positive.
(D) For real and inverted images, magnification is always negative.

Hint:

Concave lenses always form virtual, upright, and diminished images, so their magnification is negative.

Answer 1

We must assess the provided statements concerning magnification for various mirrors and lenses.

1. Conceptual Foundation:

Magnification: Magnification is defined as the ratio of image height to object height, expressed by the formula \( m = \frac{h_i}{h_o} \), where \( h_i \) denotes image height and \( h_o \) denotes object height. A positive magnification indicates an upright image, while a negative magnification signifies an inverted image.

2. Statement Analysis:

Statement (A): A convex mirror always produces a negative magnification.
This statement is erroneous. Convex mirrors consistently form virtual, upright, and diminished images. Consequently, their magnification is always positive, not negative.

Statement (B): All virtual images formed by a mirror exhibit positive magnification.
This statement is accurate. Virtual images produced by mirrors, including concave and convex types, are invariably upright, leading to positive magnification values.

Statement (C): A concave lens always yields positive magnification.
This statement is accurate. Concave lenses consistently generate virtual, upright images, which correspond to positive magnification.

Statement (D): Real and inverted images invariably have negative magnification.
This statement is accurate. Real and inverted images, typically formed by concave mirrors or convex lenses, are always associated with negative magnification.

3. Conclusion:

The erroneous statement is Statement (A): "For a convex mirror, magnification is always negative." This is incorrect because convex mirrors always produce positive magnification.

Final Answer:

The incorrect statement is (A) For a convex mirror, magnification is always negative.