**Interference** differs from **diffraction** in that interference involves:
AA single wavefront, diffraction needs two
BSuperposition of waves from multiple coherent sources; diffraction is superposition from a single wavefront's secondary wavelets (bending around an obstacle/aperture)
COnly longitudinal waves; diffraction needs transverse
DHigher frequencies only
Answer & Solution
Correct answer: B. Superposition of waves from multiple coherent sources; diffraction is superposition from a single wavefront's secondary wavelets (bending around an obstacle/aperture)
Interference: two (or more) discrete coherent sources superpose (Young). Diffraction: a single wavefront bends/spreads after passing an edge/aperture and self-interferes. The distinction is sometimes blurry (e.g., single-slit diffraction = interference of secondary wavelets from one slit).
Related questions
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