Question

4.
8.
In YDSE experiment, the angular width of a fringe
formed on a distant screen is 0.5º. If light of
wavelength 7000 Å is used in the experiment, then
distance between slits is
[NCERT Pg. 364]
ra
ir
(1) 0.08 mm
(2) 0.08 cm
(3) 0.01 mm
(4) 0.02cm

Answer 1

Given:

θ =  0.5º

λ = 7000 Å

To find:

d =?

Explanation:

By YDSE experiment,

d sinθ = mλ          ....m = 1, 2, 3, ....

Here m = 1 & θ is very small

Here θ is small

θ  = $\frac{\lambda D}{d}\times \frac{1}{D}$

θ = $\frac{\lambda}{d}$

d = $\frac{7000 \times 10^{-10} }{sin0.5}$

d = 0.08 mm

Option a is correct