Question

In a double slit arrangement the slits are separated by a distance equal to 100 times the wavelength of the light passing through the slits. Find the angular separation between the central maximum and an adjacent minimum.

Answer 1

well... the condition for minima is

path difference = n times wavelength + 1/2 wavelength..
since you want the adjacent minima.. its the first minima.. hence n = 1

thus path difference = 1/2 wavelength

now if theta is angular seperation .. then path difference = 2d sin (theta) hence\[2dsin(\theta ) = \lambda / 2\]\[d = 100 \lambda \]
so find theta!