PQR is a right-angled prism with other angles as 60o and 30o. The Refractive index of the prism is 1.5. PQ has a thin layer of liquid. Light falls normally on the face PR. For total internal reflection, the maximum refractive index of the liquid is:
Correct answer: C. 1.2
- A. 1.4
- B. 1.3
- C. 1.2
- D. 1.6
Explanation
For total internal reflection to occur, the refractive index of the liquid must be less than the refractive index of the prism. In this case, the maximum refractive index of the liquid should be 1.2, which is less than the prism's refractive index of 1.5. This allows the light to undergo total internal reflection at the interface between the liquid and the prism. Options A, B, and D are incorrect because they do not meet the condition for total internal reflection to happen.
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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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