COMEDK · Physics · 25. Ray Optics
An object is placed 25 cm in front of a fully silvered concave mirror of focal length 15 cm. A plane mirror is placed 35 cm behind the concave mirror on the side opposite to the object. The final image after reflection first from the concave mirror and then from the plane mirror is formed at:
- A 37.5 cm in front of the plane mirror
- B 107.5 cm behind the concave mirror
- C 72.5 cm behind the concave mirror
- D 37.5 cm in front of the concave mirror
Answer & Solution
Correct Answer
(B) 107.5 cm behind the concave mirror
Step-by-step Solution
Detailed explanation
For the first reflection from the concave mirror: Object distance, \(u = -25\) cm Focal length, \(f = -15\) cm Using the mirror formula: \(\dfrac{1}{v} + \dfrac{1}{u} = \dfrac{1}{f}\) \(\dfrac{1}{v} - \dfrac{1}{25} = -\dfrac{1}{15}\)…
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