The sky appears blue because
Correct answer: B. shorter wavelengths are scattered more strongly by air molecules
- A. the atmosphere is blue in colour
- B. shorter wavelengths are scattered more strongly by air molecules
- C. the sea reflects onto the sky
- D. the Sun emits mostly blue light
Explanation
Rayleigh scattering varies as the inverse fourth power of wavelength, so blue is scattered far more than red and reaches the eye from all directions. At sunset the light travels a longer path through the atmosphere, so most of the blue is scattered away and the transmitted light appears red. The Sun's own output peaks in the green yellow region.
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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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