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For spherical mirrors of small apertures, the radius of curvature is found to be _______ the focal length.

This question was previously asked in
ALP CBT 2 Physics and Maths Previous Paper 2 (Held On: 21 Jan 2019 Shift 2)
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  1. half
  2. same as
  3. thrice
  4. twice

Answer (Detailed Solution Below)

Option 4 : twice
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Detailed Solution

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CONCEPT: 

  • Spherical mirror: The mirror which has a spherical reflecting surface is called a spherical mirror.

F1 N.J Madhu 20.06.20 D1

There are two types of spherical mirror:

  • Convex mirror: The spherical mirror whose reflecting surface is away from the center of curvature is called a convex mirror.
    • It always from a virtual image of any object.
  • Concave mirror: The mirror whose reflecting surface is inward is called a concave mirror.
    • It can form both real as well as virtual images of any object.

EXPLANATION:

Radius of curvature (R) = 2 × Focal length (f)

  • For spherical mirrors of small apertures, the radius of curvature is found to be twice the focal length. So option 4 is correct.
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