A single slit of width a is illuminated with monochromatic light of wavelength λ. A diffraction pattern is observed on a screen at distance D. What is the linear separation on the screen between the first and the third minima on the same side of the central maximum?
Options

Question

A single slit of width a is illuminated with monochromatic light of wavelength λ. A diffraction pattern is observed on a screen at distance D. What is the linear separation on the screen between the first and the third minima on the same side of the central maximum?

Options

G1 Physics · Accepted Answer

For single-slit diffraction, minima occur at yₙ = nλD ÷ a, for n = 1, 2, 3, ... Thus, y₁ = λD ÷ a, and y₃ = 3λD ÷ a. Therefore the separation is y₃-y₁ = 2λD ÷ a. Correct option: C.