Question

Light of wavelength 550 nm is incident as parallel beam on a slit of width 0.1 mm find the angular width and the linear width of the principal Maxima in the resulting differentiation turn on a screen kept at a distance of 1.1 m from the slate which of these width would not changed if the screen work at a distance of 2.2 m from the slit

Answer 1

Answer : -

Angular width of principa Maxima is given by,

∅ = λ / b where λ = wavelength , b = slit of width

λ = 550 nm

b = 0.1 mm

∅ = 550 x $10^{-9}$ / 0.1 x $10^{-3}$

∅ = 5.5 x $10^{-3}$ rad

Linear width = r x ∅

Linear width = 1.1 x 5.5 x $10^{-3}$

Linear width = 6.05 x $10^{-3}$

When the screen is moved at a distance of 2.2 m , angular width will remain same, however linear width will change

Linear width = r x ∅

Linear width = 2.2 x 5.5 x $10^{-3}$

Linear width = 1.21 x $10^{-2}$