Question

state the law to determine the wavelength of light from the study of fringes.​

Answer 1

Answer:

There is a solution given below:

Explanation:

Given: fringe with β=0.03 cm,D=1 m=100 cm

Distance between images of the source =0.8 cm

Image distance v=80 cm

Object distance =u

Using mirror formula,

v

1

+

u

1

=

f

1

⇒

60

1

+

u

1

=

16

1

⇒u=20 cm

Magnification, m=

u

v

=

20

80

=4

Magnification=

distance between slits

distances between images of slits

=

d

0.8

=

d

0.8

=4⇒d=0.2 cm

Fringe width β=

d

Dλ

or, β=

0.2

100λ

=0.03×10

−2

Therefore, wavelength of light used λ=6000

A

∘

.