An object is placed 15 cm from a convex lens of focal length 10 cm. The image is
A{'text': 'virtual, erect, magnified 2× and 30 cm from the lens', 'label': 'A'}
B{'text': 'real, inverted, diminished and 6 cm from the lens', 'label': 'B'}
C{'text': 'real, inverted, magnified 2× and 30 cm from the lens', 'label': 'C'}
D{'text': 'virtual, erect, diminished and 6 cm from the lens', 'label': 'D'}
Answer & Solution
Correct answer: C. {'text': 'real, inverted, magnified 2× and 30 cm from the lens', 'label': 'C'}
1. NCERT lens formula: 1/v − 1/u = 1/f, with u = −15 cm, f = +10 cm.
2. 1/v = 1/10 + 1/(−15) ⇒ 1/v = (3 − 2)/30 = 1/30 ⇒ v = +30 cm (real, opposite side).
3. m = v / u = 30 / (−15) = −2 ⇒ image is inverted and 2× magnified.
4. Distractors come from sign-convention slips and confusing convex with concave (where the same u/f sign would give a virtual diminished image).
_Source: NCERT Class 12 Physics Part II, Ch 9 §9.5.2 worked-example pattern_
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