Related InterviewSolutions

• Two stars are situated at a distance of 8 light years from the earth. These are to be just resolved by a telescope of diameter 0.25 m. If the wavelength of light used is 5000 Å, then the distance between the stars must beA. `3xx10^(10)m`B. `3.35xx10^(11)m`C. `1.95xx10^(11)m`D. `4.32xx10^(10)m`
• The distance between the first and the sixth minima in the diffraction pattern of a single slit is 0.5 mm. The screen is 0.5 m away from the slit. If the wavelength of light used is 5000 Å. Then the slit width will beA. 5 mmB. 2.5 mmC. 1.25 mmD. 1.0 mm
• A parallel beam of light of wavelength `6000Å` gets diffracted by a single slit of width 0.3 mm. The angular position of the first minima of diffracted light is :A. `6xx10^(-3)` radB. `1.8xx10^(-3)` radC. `3xx10^(-3)` radD. `2xx10^(-3)` rad
• A narrow slit of width 2 mm is illuminated by monochromatic light fo wavelength 500nm. The distance between the first minima on either side on a screen at a distance of 1 m isA. 5 mmB. 0.5 mmC. 1 mmD. 10 mm
• In double slit experiment , the distance between two slits is `0.6mm` and these are illuminated with light of wavelength `4800 Å`. The angular width of dark fringe on the screen at a distance 120 cm from slits will beA. `8xx10^(-4)` radB. `6xx10^(-4)` radC. `4xx10^(-4)` radD. `16xx10^(-4)` rad
• A parallel beam of light of intensity I is incident on a glass plate. `25%` of light is reflected in any reflection by upper surface and `50%` of light is reflected by any reflection from lower surface. Rest is refracted The ratio of maximum to minimum intensity in interference region of reflected rays is A. `(((1)/(2)+sqrt((3)/(8)))/((1)/(2)-sqrt((3)/(8))))^(2)`B. `(((1)/(4)+sqrt((3)/(8)))/((1)/(2)-sqrt((3)/(8))))^(2)`C. `(5)/(8)`D. `(8)/(5)`
• A thick glass slab `(mu= 1.5)` is to be viewed in reflected white light. It is proposed to coat the slab with a thin layer of a material having refractive index 1.3 so that the wavelength 6000 Å os suppressed. Find the minimum thickness of the coating required.
• An oil film covers the surface of a small pond. The refractive index of the oil is greater than that of water. At one point on the film, the film has the smallest non-zero thickness for which there will be destructive interference in the reflected light when infrared radiation with wavelength 800 nm is incident normal to the film. When this film is viewed at normal incidence at this same point, for what visible wavelengths, if any, will there be constructive interference? (Visible light has wavelengths between 400nm and 700 nm )
• Determine what happens to the double slits interference pattern if one of the slits is covered with a thin, transparent film whose thickness is `lambda/(2(mu-1))`, where `lambda` is the wavelength of the incident light and mu is the index of refraction of the film.
• A possible means for making an airplane invisible to radar is to coat the plane with an anti reflective polymer. If radar waves have a wavelength of 3.00 cm and the index of refraction of the polymer is `mu=1.5`. How thick is the oil film? Refractive index of the material of airplane wings is greater than the refractive index of polymer.