A parallel beam of monochromatic light of wavelength 500 nm is incident normally on a rectangular slit. The angular width of the central fringe of Fraunhofer diffraction is found to be `60^(@)`. Find the width of the slit in metre.

Explanation

To solve the problem, we will follow these steps:

### Step 1: Identify the given values
- Wavelength of light, \( \lambda = 500 \, \text{nm} = 500 \times 10^{-9} \, \text{m} \)
- Angular width of the central fringe, \( \theta = 60^\circ \)

### Step 2: Calculate the angle for the first minimum
In Fraunhofer diffraction, the angular width of the central maximum is defined as the angle between the first minima on either side of the central maximum. Therefore, we need to find half of this angle:
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