WBJEE · Physics · Ray Optics
A luminous object is separated from a screen by distance \(d\). A convex lens is placed between the object and the screen such that it forms a distinct image on the screen. The maximum possible focal length of this convex lens is
- A \(4 d\)
- B \(2 d\)
- C \(\frac{d}{2}\)
- D \(\frac{d}{4}\)
Answer & Solution
Correct Answer
(D) \(\frac{d}{4}\)
Step-by-step Solution
Detailed explanation
Focal length of a convex lens by displacement method Focal length of the convex lens \[ f=\frac{a^{2}-b^{2}}{4 a} \] where \(a\) = distance between the image and object and \(b=\) distance between two positions of lens Fact The distance bemeen the ho points should be 4 times…
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