Coherent light with wavelength 400 nm passes through two very narrow slits that

Question

Coherent light with wavelength 400 nm passes through two very narrow slits that are separated by 0.200 mm and the interference pattern is observed on a screen 4.00 m from the slits.

Part A

What is the width (in mm) of the central interference maximum?

SubmitMy AnswersGive Up

Part B

What is the width (in mm) of the first-order bright fringe?

Coherent light with wavelength 400 nm passes through two very narrow slits that are separated by 0.200 mm and the interference pattern is observed on a screen 4.00 m from the slits.

Part A

What is the width (in mm) of the central interference maximum?

SubmitMy AnswersGive Up

Part B

What is the width (in mm) of the first-order bright fringe?

Explanation / Answer

m = 1/2

= 2*arcsin(m*lambda/(d)) = 0.002 rad, 0.11459 deg

y = D*tan() = 0.008 m = 8 mm

You solve for the angle of the widths first. For both the central and 1st-order fringes, is twice the angle at which the path length difference of rays passing through the two slits equals 1/2 wavelength. Since the angles from the center are so small, the two values are very close to equal.

Answer for both the parts are:

8 mm

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects