The angle of deviation of light of various colours passing through a triangular prism increases in the order

Analyze the question: The question asks how the angle of deviation changes for different colours of light passing through a prism, listed from the smallest deviation to the largest.

Concept: When white light passes through a prism, it disperses because each colour has a different refractive index in glass.

• Red light has the longest wavelength, so it has the lowest refractive index and is bent the least.
• Violet light has the shortest wavelength, so it has the highest refractive index and is bent the most.

The order of increasing deviation follows the order of the spectrum from red to violet:

Red → Orange → Yellow → Green → Blue → Indigo → Violet

Checking the options:

• A. red → green → blue: This runs from least to most deviation. ✔
• B. green → violet → blue: Violet deviates more than blue, so this is not in increasing order. ✘
• C. blue → red → green: Red deviates the least, so it cannot come after blue. ✘
• D. blue → green → red: This is the decreasing order. ✘

Tip: Remember "ROYGBIV". Deviation increases along ROYGBIV, so red is bent least and violet is bent most. If an option lists colours in the order they appear in ROYGBIV, it shows increasing deviation.