Question

The separation between the consecutive dark fringes in a Young's double slit experiment is 1⋅0 mm. The screen is placed at a distance of 2⋅5 m from the slits and the separation between the slits is 1⋅0 mm. Calculate the wavelength of light used for the experiment.

Answer 1

Answer:

Given that, β=1 mm=10

−3

m,D=2.5 m and d=1 mm=10

−3

m

So, 10

−3

m=

10

−3

25×λ

⇒λ=4×10

−7

m=400 nm.

Answer 2

In Young's double slit experiment the separation d between the slits is 2mm, the wavelength λ of light used is 5896Ao and distance D between the screen and slits is 100cm. It is found that the angular width of the fringes is 0. 20o. To increase the fringe angular width to 0.