You are given four sources of light each one providing a light of a single colour- red, blue, green and yellow. Suppose the angle of refraction for a beam of yellow light corresponding to a particular angle of incidence at the interface of two media is 90. Which of the following statements is correct if the source of yellow light is replaced with that of other lights without changing the angle of incidence?
1. The beam of red light would undergo total interface reflection.
2. The beam of red light would bend towards normal while it gets refracted through the second medium.
3. The beam of blue light would undergo internal reflection.
4. The beam of green light would bend away from the normal as it gets refracted through the second medium.
(3) Hint: The refractive index of a medium depends on the wavelength of the light of particular colour.
Step 1: Find the relative refractive index for different colours.
According to VIBGYOR, among all given sources of light, blue light has the smallest wavelength. According to the Cauchy relationship, the smaller is the wavelength, the higher the refractive index and consequently smaller the critical angle.
Step 2: Find the relative critical angle for different colours.
So, corresponding to blue colour, the critical angle is the least which facilitates total internal reflection for the beam of blue light. The beam of green light would also undergo total internal reflection.
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