Superposition Flashcards
Superposition
When two or more same type of waves meet at a point, it is known as superposition.
Principle of Superposition
When two or more same type of waves meet at a point, net displacement of that point is equal to the vector/ algebraic sum of individual displacement of the waves.
Diffraction
When wave passes through a narrow gap or near edge of any object, it spreads into the geometrically shadow region. This phenomena is known as diffraction.
Amount of diffraction depends on:
- Wavelength (more wavelength, more diffraction)
- Width or gap/slit (less width, more diffraction)
Coherent waves
Waves of constant phase difference.
When two same type of wave of same frequency/ wavelength are moving at same direction, their phase difference is always same and they are said to be coherent waves.
Phase difference
Difference in distance travelled by waves from their source to meeting point.
Interference
When two coherent waves superpose at a point, resultant displacement of that point due to reinforcement or cancellation of each other is known as interference.
Condition of interference
- Two same types of coherent waves are required.
- They have to meet at a point.
Two types of interference
- Constructive interference
- Destructive interference
Constructive Interference
When two same types of coherent waves meet at a point with phase difference of 360/2π rad, resultant displacement of that point is equal to sum of their individual displacement. So, particle at that point will vibrate with maximum amplitude/displacement. Hence brightness/loudness/intensity will be maximum at that point.
Conditions for constructive interference
- Phase difference between waves = 360/2πrad
- Path difference between waves = nλ
Destructive interference
When two same types of coherent waves meet at point with phase difference of 180/
