Since fringe separation depends on wavelength and different colours have different wavelengths the fringes of different colours can be seen.Blue light fringes are closer together than red light fringes.The central fringe is in the same position for each so the central fringe is white light.Inner fringes are tinged with blue on the inner side and red on the outer side.Outer fringes merge into indistinct background of white light and become fainter with distance from the centre.
White Light Fringes
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Specification: AQA Physics (7407), AS-level, 3.3.2.2 Diffraction and 3.3.2.1 Interference. Topic: Optics.
Key terms in this lesson
- Vector quantity
- A physical quantity that has both magnitude and direction.
- Equilibrium
- An object is in equilibrium when the resultant force and the resultant moment acting on it are both zero.
- Moment
- The turning effect of a force about a pivot, equal to the force multiplied by the perpendicular distance from the pivot to the line of action of the force.