Mirror focal length f and radius R relation: MCQ with Answer and Explanation

Mirror focal length f and radius R relation:
A. f = R/2
B. f = 2R
C. f = R
D. f = R²
Answer: Option A
Solution (By JKExamLibrary)
Spherical mirrors: f = R/2 under paraxial approximation. Derived from geometry of reflection. Memory tip: 'Mirror: f = R/2; sign: concave +, convex -'. Optics formula frequently tested in competitive exams.

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