Light of wavelength 500 nm in a vacuum enters glass of refractive index 1.5. Inside the glass its wavelength becomes
Correct answer: B. 333 nm
- A. 750 nm
- B. 333 nm
- C. 500 nm
- D. 250 nm
Explanation
Frequency is unchanged on entering a medium, and since the speed falls by the factor of the refractive index the wavelength must fall in the same proportion, giving 500 divided by 1.5, which is about 333 nm. The colour perceived does not change, because it is determined by frequency. Multiplying instead gives the 750 nm distractor.
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About Optics
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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