Two coherent light beams of wavelength meet at a point on a screen where they…
PHYSICS · Single correct · A Level · Physics · Waves · Waves
Problem
Two coherent light beams of wavelength 600nm meet at a point on a screen where they currently produce complete destructive interference. What is the minimum additional distance that one of the beams must travel (for example, by moving a mirror) so that the same point on the screen instead exhibits complete constructive interference?
(a) 600nm
(b) 150nm
(c) 300nm
(d) 900nm