Question

In Young’s double slit experiment, using sodium light (
  5898
Å), 92 fringes are seen. If another colour (
  5461
Å) is used then find the number of frin

Answer 1

Answer:

Let the length of the screen on which the fringes are obtained be L

0

.

Thus the fringe width if 92 fringes are obtained is

92

L

0

.

We know that fringe width =

d

Dλ

Hence, for new wavelength λ

′

, let there be n fringes.

Thus

d

Dλ

′

=

n

L

0

Thus n=92

λ

′

λ

=99