In Young.s double slit experiment, what is meant by .fringe separation. ? State two ways of increasing the fringe width, without changing the source of light.

Explanation

### Step-by-Step Solution

**Step 1: Define Fringe Separation**
Fringe separation, also known as fringe width, is the distance between two consecutive bright (maxima) or dark (minima) fringes in an interference pattern created by Young's double slit experiment. It can be mathematically expressed as:
\[ \beta = \frac{\lambda D}{d} \]
where:
- \( \beta \) = fringe separation (width)
- \( \lambda \) = wavelength of the light used
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