Assuming the mean wavelength of light as `555 nm`, estimate the smallest angular separation of two stars which can be just resolved by the telescope. Given the diameter of objective of astronomical telescope is `25 cm`.

Explanation

To solve the problem of estimating the smallest angular separation of two stars that can be just resolved by an astronomical telescope, we will follow these steps:

### Step 1: Convert Wavelength to Meters
The mean wavelength of light is given as \( 555 \, \text{nm} \). We need to convert this into meters.

\[ \lambda = 555 \, \text{nm} = 555 \times 10^{-9} \, \text{m} \]
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