superposition Flashcards
Principle of Supersposition
superposition
when 2 or more waves meet at a point, the resultant displacement at that point is the vector sum of the displacements of the individual waves at that point
Interference definition
superposition
an effect that occurs when 2 or more waves overlap & it follows the principle of superposition
Phase Difference definition
superposition
measure of the fraction of a cycle that one wave is moving out of step with the another wave
Coherence definition
superposition
constant phase difference between the waves (or sources of waves) with time
Conditions for Observable Interference
superposition
- the sources or waves are coherent
- waves from sources have similar amplitudes
- waves from the sources must overlap
- waves are of the same type
- for polarised transverse waves, waves must have the same plane of polarisation
Diffraction definition
superposition
spreading of waves after passing through a slit or around an edge of an obstacle
Limit of Resolution / Resolving Power of an Aperture
superposition
occurs when the central maximum of the 2nd source coincides with the first minimum of the 1st source
Types of Interference
superposition
- constructive
- destructive
Constructive waves definition
superposition
waves that are in-phase and superpose to produce maximum amplitude and intensity
Destructive waves definition
superposition
waves that are in anti-phase and superpose to produce minimum amplitude and intensity
Natural Frequencies
string
- 2 nodes at the end
tube
- node at closed end & antinode at open end
- 2 antinodes at open ends
why are bright fringes produced?
- waves from 2 slits overlap and superpose at points on the screen
- when path difference from slits to the point is multiples of the wavelengths / phase difference is multiples if 2pi
- constructive interference give bright fringes
