NEETPhysicsRay Optics
A concave mirror of focal length 10 cm and a plane mirror are placed facing each other, separated by a distance of 20 cm along their common principal axis. A small linear object is placed exactly midway between them, perpendicular to the axis. Consider the image formation process where light from the object first reflects from the plane mirror and then from the concave mirror. Read the following statements: (A) The i
Options
- A1
- B2
- C4
- D3
Correct answer
D. 3
Step-by-step solution
The object is at 10 cm from the plane mirror. The plane mirror forms a virtual image I₁ at 10 cm behind it. Statement (A) is incorrect: The rays from I₁ diverge towards the concave mirror. Therefore, I₁ acts as a real object for the concave mirror, not a virtual object. Statement (B) is correct: The distance of I₁ from the concave mirror is the separation between the mirrors plus the distance of I₁ behind the plane mirror = 20 cm + 10 cm = 30 cm . Statement (C) is correct: For the concave mirror, u = -30 cm and f =