Assume that light of wavelength 600 nm is coming from a star. The limit of resolution of telescope whose objective has a diameter of 2 m is :
In Young's double-slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes:
2. four times
The Brewster's angle for an interface should be:
1. 30° < <45°
2. 45° < < 90°
3. = 90°
4. 0° < < 30°
Two coherent sources of light interfere and produce fringe pattern on a screen. For the central maximum, the phase difference between the two waves will be:
In a double-slit experiment, when the light of wavelength 400 nm was used, the angular width of the first minima formed on a screen placed 1 m away, was found to be 0.2. What will be the angular width of the first minima, if the entire experimental apparatus is immersed in water?
In Young's double-slit experiment, if there is no initial phase difference between the light from the two slits, a point on the screen corresponding to the fifth minimum has path difference :
The angular width of the central maximum in the Fraunhofer diffraction for . When the same slit is illuminated by another monochromatic light, the angular width decreases by 30%. The wavelength of this light is:
Unpolarised light is incident from the air on a plane surface of a material of refractive index 'μ'. At a particular angle of incidence 'i', it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?
1. The reflected light is polarised with its electric vector parallel to the plane of incidence.
2. The reflected light is polarised with its electric vector perpendicular to the plane of incidence.
In Young's double-slit experiment, the separation d between the slits is 2 mm, the wavelength of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the fringe angular width to 0.21° (with same and D) the separation between the slits needs to be changed to:-
1. 1.8 mm
2. 1.9 mm
3. 2.1 mm
3. 1.7 mm
The ratio of resolving powers of an optical microscope for two wavelengths =4000 and is: