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