Interference arises from the principle of superposition, where overlapping waves add algebraically to produce constructive or destructive interference.
Bragg's law for diffraction by crystal planes is 2d sinθ = nλ, relating spacing d, angle θ and wavelength λ.
1524
In Young's double slit experiment, if the separation between the two slits is reduced by a factor of two, then for a constant wavelength and constant distance between the slits and the screen the fringe-width will be:
Fringe width β = λD/d, so halving the slit separation d doubles β; thus the fringe-width increases by a factor of two.
1525
A double slit arrangement produces interference fringes for sodium light (λ = 589 nm) that have an angular separation of 3.50 × 10⁻¹ radian. For what wavelength would the angular separation be 10% greater ?
Angular separation is proportional to wavelength, so a 10% larger angle requires a wavelength 1.1×589 nm ≈ 648 nm (closest option 645 nm).
1526
A yellow light of wavelength 500 nm emitted by a single source passes through two narrow slits 1 mm apart. How far apart are two adjacent bright fringes when interference is observed on a screen 10 m away?
Fringe spacing y = λD/d = (500×10^-9 m × 10 m)/(1×10^-3 m) = 5×10^-3 m = 5 mm.
1527
In a Fresnel biprism experiment, the two positions of lens give separation between the slits as 16 cm and 9 cm respectively. What is the actual distance of separation?
