Home › NEET UG › Physics › Ray Optics and Optical Instruments ›  An object is placed at 10 cm in front of a concave mirror of radius of curvature 15 cm. The image is formed at:
A5 cm in front of the mirror, virtual
B30 cm in front of the mirror, real and inverted, magnified 3 ×
C30 cm behind the mirror, virtual
D10 cm in front, same size
Answer & Solution
Correct answer: B. 30 cm in front of the mirror, real and inverted, magnified 3 ×
f = −R/2 = −7.5 cm; u = −10 cm. Mirror eqn: 1/v = 1/f − 1/u = 1/(−7.5) − 1/(−10) = −0.1333 + 0.1 = −0.0333 → **v = −30 cm** (real, same side as object). m = −v/u = −(−30)/(−10) = **−3** (inverted, magnified 3×).
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