2.4 Superposition and Interference of Waves

Question 1

Diffraction

Answer 1

spreading out of waves as they pass around an obstacle or go through a gap

Question 2

when does max diffraction occur?

Answer 2

wavelength of wave equal to size of gap

Question 3

principle of superposition

Answer 3

resultant displacement when two or more waves meet at a point is the vector sum of the displacements of the individual waves at that point

Question 4

constructive interference

Answer 4

waves superimpose resulting in a wave of larger amplitude

Question 5

destructive interference

Answer 5

waves superimpose resulting in a wave of smaller amplitude

Question 6

interference pattern

Answer 6

pattern showing some areas where there is constructive interference and a large wave disturbance (maxima), and other areas where there is destructive interference and little or no wave disturbance (minima)

Question 7

what has to happen for an observable interference pattern?

Answer 7

same type of wave
coherent sources - same wavelength + frequency so constant phase difference
comparable amplitudes

Question 8

complete destructive interference

Answer 8

2 waves with equal amplitudes, meet 180o out of phase, will be total destructive interference and waves will cancel each other out