Advertisements
Advertisements
प्रश्न
Explain how interference in wedge shaped film is used to test optical flatness of given glass plate.
उत्तर
1.The phenomenon of interference is used in testing the plainness of the surface of glass plate.
2.If two surfaces OA and OB are perfectly plane,the air film between them would gradually vary in thickness from O to A.The fringes are of equal thickness as each fringe is the locus of points at which the thickness of the film has a constant value.
3.To test the optical flatness of a surface,the specimen surface to be tested(OB) is placed overan optically plane surface (OA).
4.The fringes are observed in the field of view.
5.If the fringes are of equal thickness then surface is plane.
6.If the fringes are not of equal thickness then surface is not plane.
7.In this way interference in wedge shaped film is used to test optical flatness of given glass plate.
APPEARS IN
संबंधित प्रश्न
What will be the fringe pattern if wedge shaped air film is illuminated with white light?
A wedge shaped air film having angle 40 seconds is illuminated by monochromatic light. Fringes are observed vertically through a microscope. The distance between 10 consecutive dark fringes is 1.2 cm. find the wavelength of monochromatic light used.
A wedged shaped air film having an angle of 40 seconds is illuminated by monochromatic light and fringes are observed vertically through a microscope. The distance measured between consecutive fringes is 0.12 cm. Calculate wavelength of light used.
A parallel beam of light of wavelength 5890 A0 is incident on a glass plate having refractive index 𝝁=𝟏.𝟓 such that the angle of refraction in the plate is 600. Calculate the smallest thickness of the glass plate which will appear dark by reflected light.
