What is the width of the central maximum (in cm) in the diffraction - ProProfs Discuss

# What is the width of the central maximum (in cm) in the diffraction pattern on a screen 5.0m away from a single slit 1.00mm wide which is illuminated by 450nm light?

A. 3 cm
B. 0.8 cm
C. 0.45 cm
D. 0.5 cm
E. None of the Above

This question is part of Single Slit Diffraction Quiz
Asked by Kramayp, Last updated: Apr 02, 2020

#### Danny R. Glover

Danny R. Glover, Editor, New York City

The answer to this is C. The width is 0.45 cm. The width of the central max is inversely proportional to the slit’s width. The central maximum is known to be the area wherein the light is the most intense and the brightest. Remember n=1, n=450 10x-9m. D=5.0m. To compute for d, you need to do this formula d=1 10x-3m.

You need to multiply the answer that you will get by 2 in order to get the correct answer for central max. If you would follow the formulas mentioned above, you will get letter C as you answer. You can try it out to see if you are going to get the same results.

#### John Smith

John Smith

0.45 cm

Use the equation with n = 1,= 450 10^-9m, D = 5.0m and d = 1 10^-3m. Find Yn and then multiply it by 2 to get the width of the central max.

1

Replied on Nov 15, 2017

Why need to times 2?