Final answer:
The angular width of the central fringe in a multiple-slit interference pattern is determined by dividing the wavelength by the slit separation.
Step-by-step explanation:
The question is asking about the angular width of the central fringe in a multiple-slit interference pattern, specifically for scenarios with 20 and 50 slits with a given separation.
The general formula for the angular width of a central fringe in multiple-slit interference is Θ = λ/d. For the case of 20 slits and 50 slits with the same separation, we would simply apply this formula with the given slit separation distances (d) and the wavelength (λ) of the light.
Assuming a wavelength (λ) of 600 nm, and given slit separation (d) of 2.0 × 10⁻³ mm, the respective angular widths can be calculated.