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Course: Optics (Essentials) - Class 12th > Unit 5

Lesson 3: How can light + light give darkness?
Science
Optics (Essentials) - Class 12th
Why do bubbles appear colorful?
How can light + light give darkness?
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Double-slit experiment: fringe widths (one wavelength)

Google Classroom

Problem

A double-slit experiment is setup with two slits 0.8 mm apart and the screen placed 70 cm from the plane of the slits.
When monochromatic light is shone on the slits, it's seen that the tenth bright fringe is 5.6 cm from the central bright fringe.
What is the wavelength of the light?
Note: Input answer in units of nm.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
nm