Red light of wavelength 633 nmnm from a helium-neon laser passes through a slit 0.400 wide. The diffraction pattern is observed on a screen 2.90 mm away. Define the width of a bright fringe as the distance between the minima on either side. Required:
a. What is the width of the central bright fringe?
b. What is the width of the first bright fringe on either side of the central one?

a

b

Explanation:

From the question we are told that

   The wavelength of the red light is  

    The width of the slit is  

    The distance of the screen from the point of diffraction is

Generally the width of the central bright fringe is mathematically represented as

=>    

=>    

Generally the width of the first bright fringe on either side of the central one is mathematically represented as

=>  

=>