JEE Mains · Physics · STD 12 - 9. Ray optics and optical instruments
A concave mirror produces an image of an object such that the distance between the object and image is 20 cm . If the magnification of the image is ' -3 ', then the magnitude of the radius of curvature of the mirror is :
- A \(30\mathrm{~cm}\)
- B \(3.75\mathrm{~cm}\)
- C \(15\mathrm{~cm}\)
- D \(7.5\mathrm{~cm}\)
Answer & Solution
Correct Answer
(C) \(15\mathrm{~cm}\)
Step-by-step Solution
Detailed explanation
\(\begin{aligned} & m=-3=-\frac{u}{v} \\ & u=-x \\ & v=-3 x \\ & \Rightarrow 2 x=20 \mathrm{~cm}\end{aligned}\)…
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