In Young’s double-slit interference experiment, if the slit separation is made threefold, the fringe width becomes 


Correct option is



Thus .



Two identical coherent sources are placed on a diameter of a circle of radius R at separation x (<< R) symmetrical about the centre of the circle. The sources emit identical wavelength λ each. The number of points on the circle of maximum intensity is (x = 5λ).  


In Young’s double-slit experiment  (d = distance between slits, D = distance of screen from the slits). At a point P on the screen, resulting intensity is equal to the intensity due to the individual slitI0. Then, the distance of point P from the central maximum is (λ = 6000 Ã…)


To produce a minimum reflection of wavelength near the middle of visible spectrum (550 nm) how thick should a coating of MgF(μ = 1.38) be vacuum-coated on a glass surface?   


A thin film of refractive index 1.5 and thickness 4 × 10–5 cm is illuminated by light normal to the surface. What wavelength within the visible spectrum will be intensified in the reflected beam?


A plane wave of monochromatic light falls normally on a uniform thin film of oil which covers a glass plate. The wavelength of source can be varied continuously. Complete destructive interference is observed for λ = 5000Ã… and λ = 1000 Ã… and for no other wavelength in between. If μ of oil is 1.3 and that of glass is 1.5, the thickness of the film will be  


A light ray frequency v and wavelength λ enters a liquid of refractive index . The ray travels in the liquid with  


In a double-slit experiment, instead of taking slits of equal width, one slit is made twice as wide as the other. Then, in the interference pattern


Light of wavelength λ = 5890 Ã… falls on a double-slit arrangement having separation d = 0.2 mm. A thin lens of focal length f = 1 m is placed near the slits. The linear separation of fringes on a screen placed in the focal plane of the lens is   


In Young’s double-slit experiment, the two slits act as coherent sources of equal amplitude A and of wavelength λ. In another experiment with the same setup, the two slits are sources of equal amplitude A and wavelengthλ, but are incoherent. The ratio of intensity of light at the mid-point of the screen in the first case to that in the second case is  


Sources 1 and 2 emit lights of different wavelengths whereas 3 and 4 emit lights of different intensities. The coherence