Three letters are written on the internal base of a glass beaker in three different colours, red, blue and green. Now, the beaker is filled with the water. Which of the following coloured letter will be seen least raised when seen through the water ?

Explanation

To determine which colored letter will be seen least raised when viewed through water in a glass beaker, we can analyze the situation using the principles of refraction and the refractive indices of different colors of light.

### Step-by-Step Solution:

1. **Understanding Refraction**: When light passes from one medium to another (in this case, from water to air), it bends due to a change in speed. This bending causes objects to appear raised or shifted from their actual position.

2. **Refractive Index**: The refractive index (μ) of a medium is a measure of how much light slows down in that medium compared to its speed in a vacuum. Different colors of light have different wavelengths and thus different refractive indices when passing through a medium.

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