A soap flm of refractinve index `4//3` is illuminated by white light incident at an angle `45^@`.The transmitted length is examined in a spectroscope and a brigth band is found to be at `6,000 overset @A`.Find the minimum thickness of the film.

In Young's double slit experiment ,the central bright fringe produced by ligth of wavelength 5,600 overset@A shifts to the position of 5th brigth fringe,when thin transparent film of refractive index 1.28 is introduced in the path of light from one of two slits.Find the thickness of te film.

A thin film is 4,000 overset @A thick. White light from an extended source falls normally on the film.If the refractive index of film is 1.5,what wavelength within the visible spectrum will be intenisifed in the reflected beam ,if visible range of the spectrum is 3,900 overset @A to 7,800 overset @A ?

The Young's double-slit experiment is done in a medium of refractive index 4//3. A light of 600 nm wavelength is falling on the slits having 0.45 mm separation. The lower shift S_(2) is covered by a thin glass sheet of thickness 10.4 mm and refractive index. 1.5. The interference pattern is observed on a screen placed 1.5 m from the slits as shown in Figure Find the light intensity of point O relative to the maximum fringe intensity.

Using light of wavelength 6,000 overset@A ,it is found that in a thin film of air,7 fringes occur between two points,deduce the difference of the film thickness between these points.

A ray of light is incident on a prism ABC of refractive index sqrt3 as shown in Fig.3.14. Find the angle of incidence for which the deviation of light ray by the prism ABC is minimum. .

A prism of refractive index mu_1 and another prism of refractive index mu_2 are struck together without a gap as shown in Fig.3.17. . The ngles of the prisms are shown . mu_1 and mu_2 depend on delta ,the wavelength of light according to mu_1=1.20 +(10.8 xx 10^4)/(delta^2) and mu_2 = 1.45 + (1.8 xx 10^4)/(delta^2) , where delta is in nm. Calculate the wavelength delta_0 for which rays incident at any angle on the interface BC pass through without bending at that interrface.

Monochromatic ligth of wavelgth 6,000 overset @A is used in a Young's double slit experiment.One of the slits is covered by a transparent film of thickness 1.2 xx 10^(-5) m having refractive index 1.4.How many fringes will shift due to the introduction of the film?

A door of length 2 m and breadth 1m is fitted in a wall. The length of the wall is 4.5 m and the breadth is 3.6 m . Find the cost of white washing the wall, if the rate of white washing the wall is Rs. 20 per m^2 .

Lenses are often coated with a thin film to reduce the intesntiy of reflected light. If the index of refraction of the coating is 1.3 ,what is the smallest thickness that wilo give minimum relfaction of yello light (lambda=5,800 overset@A) ?

Light of wavelength 6,000 overset @A is incident on a thin film of refractive index 1.5 ,such that angle of refraction into the film in 60^@ .Calculate the smallest thickness of the film,which will make it appear dark by reflection.