Question

Which one of the following phenomena cannot be attributed to the refraction of light?
A. Twinkling of stars
B. Mirage
C. Rainbow
D. Redshift

Answer 1

Hint:The phenomenon that can’t be attributed to the refraction of light is the variation in frequency of any sound or light wave produced by a moving source with relation to an observer. As an object approaches an observer, the waves it emits become compressed, resulting in a greater frequency.

Complete answer:
Refraction of light causes stars to twinkle, mirages to appear, and rainbows to appear, but the Doppler effect causes redshift.The Doppler Effect is exemplified by redshift. The sound or light waves released by an object stretch out as it moves away from us, giving them a lower pitch and moving them towards the red end of the electromagnetic spectrum, where light has a longer wavelength.

The phrase essentially means that the wavelength of light is stretched, causing the light to shift' towards the red section of the spectrum. When a source of sound moves in relation to an observer, something similar happens to sound waves.In physics, a redshift is a rise in the wavelength of electromagnetic radiation with a corresponding drop in frequency and photon energy (such as light). A negative redshift, or blueshift, is defined as a drop in wavelength with a concomitant rise in frequency and energy. The words are derived from the colours red and blue, which are the visible light spectrum's extremes.

Hence, the correct option is (D).

Note: In RADAR sensors, the Doppler effect is employed to quantify speed. When a fixed-frequency radio wave sent from the sender constantly encounters an object moving towards or away from the sender, the frequency of the reflected radio wave is changed.