Two convex lenses of equal focal length 'f' are placed in contact; the resultant focal length of the combination is:
Correct answer: C. 2f
- A. Zero:
- B. f:
- C. 2f
- D. f/2:
Explanation
Explanation: When two convex lenses are in contact, their focal lengths add up. Therefore, the resultant focal length is 2f. In general, the effective focal length of a system of lenses in contact is influenced by the individual focal lengths and the separation between the lenses. The formula considers the lens characteristics and their arrangement to calculate the effective focal length.
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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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