1. A glass plate of refractive index 1.6 is in contact with another
glass plate of refractive index 1.8 along a line such that a wedge of
0.5° is formed. Light of wavelength 5000 Å is incident vertically on the
wedge and the film is viewed from the top. Calculate the fringe
spacing. The whole apparatus is immersed in an oil of refractive index
1.7. What will be the qualitative difference in the fringe pattern and
what will be the new fringe width? Get solution
2. Two plane glass plates are placed on top of one another and on one side a cardboard is introduced to form a thin wedge of air. Assuming that a beam of wavelength 6000 Å is incident normally, and that there are 100 interference fringes per centimeter, calculate the wedge angle. Get solution
3. Consider a non-reflecting film of refractive index 1.38. Assume that its thickness is 9 × 10–6 cm. Calculate the wavelengths (in the visible region) for which the film will be non-reflecting. Repeat the calculations for the thickness of the film to be 45 × 10–6 cm. Show that both the films will be non – reflecting for a particular wavelength but only the former one will be suitable. Why? Get solution
4. In the Newton’s rings arrangement, the radius of curvature of the curved side of the plano –convex lens is 100 cm. For λ = 6 × 10–5 cm what will be the radii of the 9th and 10th bright rings? Get solution
5. In the Newton’s rings arrangement, the radius of curvature of the curved surface is 50 cm. The radii of the 9th and 16th dark rings are 0.18 cm and 0.2235 cm. Calculate the wavelength. [Hint: The use of Eq. (66) will give wrong results, why?) Get solution
6. In the Newton’s rings arrangement, if the incident light consists of two wavelengths 4000Å and 4002Å calculate the distance (from the point of contact) at which the rings will disappear. Assume that the radius of curvature of the curved surface is 400 cm. Get solution
7. In Problem 15.6 if the lens is slowly moved upward, calculate the height of the lens at which the fringe system (around the center) will disappear. Get solution
8. An equiconvex lens is placed on another equiconvex lens. The radii of curvature of the two surfaces of the upper lens are 50 cm and those of the lower lens are 100 cm. The waves reflected from the upper and lower surface of the air film (formed between the two lenses) interfere to produce Newton’s rings. Calculate the radii of the dark rings. Assume λ = 6000 Å. Get solution
9. In the Michelson interferometer arrangement, if one of the mirrors is moved by a distance 0.08 mm, 250 fringes cross the field of view. Calculate the wavelength. Get solution
10. The Michelson interferometer experiment is performed with a source which consists of two wavelengths 4882 Å and 4886 Å. Through what distance does the mirror have to be moved between two positions of the disappearance of the fringes? Get solution
11. In the Michelson interferometer experiment, calculate the various values of θ′ (corresponding to bright rings) for d = 5 × 10–3 cm. Show that if d is decreased to 4.997 × 10–3 cm, the fringe corresponding to m = 200 disappears. What will be the corresponding values of θ′? Assume λ = 5 × 10–5 cm. Get solution
2. Two plane glass plates are placed on top of one another and on one side a cardboard is introduced to form a thin wedge of air. Assuming that a beam of wavelength 6000 Å is incident normally, and that there are 100 interference fringes per centimeter, calculate the wedge angle. Get solution
3. Consider a non-reflecting film of refractive index 1.38. Assume that its thickness is 9 × 10–6 cm. Calculate the wavelengths (in the visible region) for which the film will be non-reflecting. Repeat the calculations for the thickness of the film to be 45 × 10–6 cm. Show that both the films will be non – reflecting for a particular wavelength but only the former one will be suitable. Why? Get solution
4. In the Newton’s rings arrangement, the radius of curvature of the curved side of the plano –convex lens is 100 cm. For λ = 6 × 10–5 cm what will be the radii of the 9th and 10th bright rings? Get solution
5. In the Newton’s rings arrangement, the radius of curvature of the curved surface is 50 cm. The radii of the 9th and 16th dark rings are 0.18 cm and 0.2235 cm. Calculate the wavelength. [Hint: The use of Eq. (66) will give wrong results, why?) Get solution
6. In the Newton’s rings arrangement, if the incident light consists of two wavelengths 4000Å and 4002Å calculate the distance (from the point of contact) at which the rings will disappear. Assume that the radius of curvature of the curved surface is 400 cm. Get solution
7. In Problem 15.6 if the lens is slowly moved upward, calculate the height of the lens at which the fringe system (around the center) will disappear. Get solution
8. An equiconvex lens is placed on another equiconvex lens. The radii of curvature of the two surfaces of the upper lens are 50 cm and those of the lower lens are 100 cm. The waves reflected from the upper and lower surface of the air film (formed between the two lenses) interfere to produce Newton’s rings. Calculate the radii of the dark rings. Assume λ = 6000 Å. Get solution
9. In the Michelson interferometer arrangement, if one of the mirrors is moved by a distance 0.08 mm, 250 fringes cross the field of view. Calculate the wavelength. Get solution
10. The Michelson interferometer experiment is performed with a source which consists of two wavelengths 4882 Å and 4886 Å. Through what distance does the mirror have to be moved between two positions of the disappearance of the fringes? Get solution
11. In the Michelson interferometer experiment, calculate the various values of θ′ (corresponding to bright rings) for d = 5 × 10–3 cm. Show that if d is decreased to 4.997 × 10–3 cm, the fringe corresponding to m = 200 disappears. What will be the corresponding values of θ′? Assume λ = 5 × 10–5 cm. Get solution
