When a beam of white light passes through a glass prism, the colour of light beam that deviates the least is
Blue
Red
Green
Violet
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-1 – 2019
– This phenomenon is called dispersion. The spectrum of white light in order of increasing wavelength (and decreasing frequency) is Violet, Indigo, Blue, Green, Yellow, Orange, Red (VIBGYOR).
– The deviation experienced by light passing through a prism is related to the refractive index of the material for that color. Generally, refractive index decreases with increasing wavelength.
– Longer wavelengths (like red) are refracted less, meaning they deviate less from their original path.
– Shorter wavelengths (like violet) are refracted more, meaning they deviate the most.
– Therefore, red light deviates the least, and violet light deviates the most.