Question 411: Waves Optics

Question

In Young’s double slit experiment the
separation d between the slits is 2 mm, the
wavelength $$\lambda $$ of the light used is 5896 $$\mathop A\limits^0 $$ and
distance D between the screen and slits is
100 cm. It is found that the angular width of
the fringes is 0.20o. To increase the fringe
angular width to 0.21o (with same $$\lambda $$ and D)
the separation between the slits needs to be
changed to

Accepted Answer

Angular width = $${\lambda  \over d}$$
$$ 	herefore $$ 0.20
o
= $${\lambda  \over 2}$$
$$ \Rightarrow $$ $$\lambda $$ = 0.2 $$ 	imes $$ 2
Again, 0.21
o
= $${\lambda  \over d}$$
So using value of ÃÂ», we have
d = $${{0.20 	imes 2} \over {0.21}}$$ = 1.9 mm

Answer

1.9 mm

Answer

1.8 mm

Answer

2.1 mm

Answer

1.7 mm

Waves Optics

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