The minimum distance between an object and its real image in a convex lens is_____________?
Correct answer: D. 4f
- A. 2 f
- B. 2.5 f
- C. 3f
- D. 4f
Explanation
For a convex lens, the separation between a real object and its real image is minimum when the object and image are both at 2f. Their separation is then 2f + 2f = 4f. The likely mistake is choosing a, 2f, by confusing the object or image distance from the lens with the distance between the object and image.
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Light is studied through reflection, refraction, dispersion, interference, diffraction and polarization, linking ray behavior with its wave nature. Questions may involve mirrors, lenses, optical instruments, refractive index and image formation, while geometrical optics deals with rays and wave optics explains effects such as interference and diffraction.
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