Single-Slit Diffraction Pattern

Steps:

• Laser light passes through a narrow slit, acting as a coherent wave source.
• Diffraction causes the light to spread out, with interference creating bright and dark fringes.
• For a vertical slit, the pattern extends horizontally due to wave superposition.
• The central maximum forms a wide horizontal bright band, flanked by fainter fringes.

Why B is correct:

• Single-slit diffraction produces a central bright horizontal line (maximum) perpendicular to the slit orientation, per the diffraction formula θ = λ/a where θ is the angle, λ is wavelength, and a is slit width.

Why the others are wrong:

• A: A dot indicates no diffraction, like geometric optics for a wide aperture.
• C: Vertical line would occur for a horizontal slit, not the typical narrow vertical slit.
• D: Shaded circle suggests circular aperture diffraction, not a slit.

Final answer: B