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JEE Main20254 Apr 2025Morning ShiftPhysicsRay OpticsActual

When an object is placed 40 cm away from a spherical mirror an image of magnification 1 2 is produced. To obtain an image with magnification of 1 3 , the object is to be moved :

Options

  1. A40 cm away from the mirror.
  2. B80 cm away from the mirror.
  3. C20 cm towards the mirror.
  4. D20 cm away from the mirror.

Correct answer

A. 40 cm away from the mirror.

Step-by-step solution

aligned & m = 1 2 = f f - u & 1 2 = f f -(-40) & f +40=2 f f =40 ~cm & now m = 1 3 = 40 40- u & 40- u =120 u =-80 aligned

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