superposition

Question 1

principle of superposition

Answer 1

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

Question 2

interference

Answer 2

effect that occurs when two or more waves overlap, the displacement at each point in the overlapping region is the vector sum of the displacements of the overlapping waves

Question 3

phase difference (superposition)

Answer 3

measure of the fraction of a cycle that one wave is moving out of step with another wave.

Question 4

coherence

Answer 4

constant path difference between the waves/sources of waves with time

Question 5

path difference

Answer 5

difference in distances that one wave travels compared to another wave from the sources to reach a particular point

Question 6

conditions for observable interference (3)

Answer 6

• waves/sources are coherent
• waves have similar amplitude
• same type of wave (for polarised, along the same plane of polarisation)
• waves must overlap

Question 7

diffraction

Answer 7

spreading of waves after passing through a slit or around the edge of an obstacle

Question 8

limit of resolution (rayleigh criterion)

Answer 8

when the central maximum of the second source coincides with the first minimum of the first source. (sinθ = λ/b)