Answer:
slit width, b = 0.2671 mm
Given:
distance of screen from the slit, x = 60.0 cm
wavelength of light, [tex]\lambda = 690 nm = 690\times 10^{- 9} m[/tex]
distance between 1st and 3rd minima, t = 3.10 mm = [tex]3.10\times 10^{-3} m[/tex]
Solution:
Calculation of the distance between 1st and 3rd minima:
[tex]t = \frac{(3 - 1)\lambda x}{b}[/tex]
[tex]3.10\times 10^{- 3} = \frac{2\times 690\times 10^{-9}\times 60.0\times 10^{-2}}{b}[/tex]
b = 0.2671 mm
slit width, b = 0.2671 mm