Answer:
Explanation:
slit separation d = 1.13 x 10ā»Ā³ m
screen distance D = 3.75 m
wavelength of light Ī» = 647 x 10ā»ā¹ m
Distance of first bright fringe = fringe width = Ī» D / d
Ī» D / d Ā = 647 x 10ā»ā¹ x 3.75 m / 1.13 x 10ā»Ā³ m
= 2.147 x 10ā»Ā³ m
= 2.147 mm .
Distance of first bright fringe = 2.147 mm .
Distance of second Ā dark Ā fringe = 1.5 x fringe width
= 1.5 x 2.147 mm .
= 3.22 mm .