Monochromatic means:

  1. of a single amplitude
  2. of one polarization
  3. of one direction
  4. of a single frequency (wavelength)
Answer

D) of a single frequency (wavelength)

Coherent sources must be monochromatic. SLO P-11-D-14 · Understanding

Physics MCQ · More Superposition, Stationary Waves and Beats MCQs · Practise