Superposition

Question 1

Principle of superposition

Answer 1

States that when two or more waves of the same type, meet at a point in space, the resultant displacement of the waves at any point is the vector sum of the displacement due to each wave acting independently

Question 2

Stationary waves

Answer 2

Waves whose waveform does not advance and there is no translation of energy. The amplitude of the waves varies according to position from zero at the nodes to a maximum at the antinodes

Question 3

How are stationary waves formed

Answer 3

When two progressive waves of the same amplitude and same frequency traveling with the same speed in opposite directions are superposed, a stationary wave is formed

Question 4

Characteristics of stationary waves

Answer 4

1. Waveform of stationary wave does not move, implying that no energy is transferred along the original direction of propagation of the progressive waves.
2. Nodes do not oscillate at all
3. Antinodes have largest amplitude
4. Distance between adjacent nodes/antinodes = half a wavelength
5. All the points between adjacent nodes/antinodes are in phase though they do not have same amplitude

Question 5

Diffraction

Answer 5

Is the spreading of waves at an edge or a slit so that the waves do not travel in a straight line
(Note: if wave encounters an opening whose diameter is much larger than wavelength, the wave emerging continues to move in a straight line)

Question 6

Coherence

Answer 6

Sources are coherent if they have constant phase difference

Question 7

Interference

Answer 7

An effect that occurs when two or more waves overlap to produce a new wave pattern

Question 8

Conditions for observable interference pattern

Answer 8

1. The waves must overlap to produce regions of maxima and minima
2. The sources must be coherent
3. The waves must be same amplitude(or approximately)
4. The waves must be unpolarized or with the same plane of polarization

Question 9

Phase difference for interference

Answer 9

Constructive: Delta x = n lamda
Destructive: Delta x = (n+0.5)lamba

Question 10

Formulas

Answer 10

Pic

Question 11

Progressive wave

Answer 11

Wave in which energy is carried from one point to another by means of vibrations or oscillations within the wave