Superposition Of Waves

Question 1

Define diffraction.

Answer 1

This is the speed of the wave after passing a gap or an obstacle.
Diffraction is greatest when the wavelength is almost the same as the size of the gap or obstacle.

Question 2

Define superposition.

Answer 2

When 2 or more waves overlap.

Question 3

State the principle of superposition of waves.

Answer 3

It states that when 2 or more waves of the same type meet at a point, the resultant displacement is the algebraic sum of the displacement of the individual waves.

Question 4

Define constructive interference.

Answer 4

When 2 waves are in phase with one another at the point they interfere constructively.

Question 5

Define destructive interference.

Answer 5

When 2 waves are completely out of phase with one another at the point they interfere destructively.

Question 6

Define path difference.

Answer 6

This is the difference in the distance travelled by a wave from its source to the receiver.

Question 7

Define coherence.

Answer 7

When 2 sources of waves have the same frequency and zero or a constant phase difference.
An interference can only be observed if the two sources of waves are coherent.

Question 8

Describe Young’s Double-Slit Experiment.

Answer 8

ax = lambda D

a - slit separation
lambda - wavelength
D - slit-screen distance
x - fringe separation