⚛️ Physics · Ray Optics and Optical Instruments · NEET & JEE

For the object at 30 cm and convex lens of focal length 20 cm (image at 60 cm), the magnification is:

Answer: 2× inverted.

A 2× erect
B 2× inverted
C 0.5× inverted
D 1×

Correct answer: B. 2× inverted

Explanation: m = v/u = 60/(−30) = −2, so the image is real, inverted, and twice the object size.

Concave mirror ray diagram with an object drawn as a candle on the principal axis, the focal point F marked, and the parallel ray and focal ray reflecting to form an inverted real image

Concave mirror ray construction: a ray parallel to the axis reflects through F, and a ray through F reflects parallel, locating the inverted real image. Image: Maxmath12, CC0, via Wikimedia Commons.

Concept context

Reflection, refraction, lenses, mirrors, total internal reflection.

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For the object at 30 cm and convex lens of focal length 20 cm (image at 60 cm), the magnification is:

Concept context

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