If the separation between the central maxima of the two objects is less then the distance between the central maximum and the first minimum of any two objects, then the two objects are said to be
Resolved
Unresolved
Well resolved
Perfectly resolved
Consider following statements regarding dispersive power of the grating and select the correct answer using codes given below:
(1).It depends upon the number of lines per unit length of the grating
(2).It depends upon the order of spectrum
(3).It depends upon Angle of diffraction.
Codes:
1 and 2 are correct
1 and 3 are correct
2 and 3 are correct
1,2 and 3 are correct
For a grating, the product of dispersive power and total effective aperture is equal to
Resolving power
Magnifying power
Limit of resolution
None of the above
When a plane wave is incident on an opaque disc then a bright spot will be formed on an axial point, spot is know as
Poisson spot
Bright spot
Black spot
All of the above
A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of the slit is
0
(/2
(
2(
In young’s double-experiment, the separation between the slits is halved and the distance between the slits and the screen is doubled. The fringe width is
Unchanged.
halved
doubled
quadrupled
/
Are parallel to each other
Are diverging
Make an angle 2|sin-1 (0.72) 30o | with each other
Make an angle 2 sin-1 (0.72) with each other
/
Straight
Circular
Equally spaced
Having fringe spacing which increases as we go outwards
In a double slit experiment instead of taking slits of equal widths, one slit is made twice as wide as the other. Then in the interference pattern
The intensities of both the maxima and the minima increase
The intensity of the maxima increases and the minima has zero intensity
The intensity of the maxima decreases and that of the minima increases
The intensity of the maxima decreases and the minima has zero intensity
Two beams of light having intensities / and 4/ interfere to produce a fringe pattern on a screen. The phase difference between the beams is (/2 at point A and ( at point B. Then the difference between the resultant intensities at A and B is
2/
4/
5/
7/
In a young’s double slit experiment, 12 fringes are observed to be formed in a certain segment of the screen when light of wavelength 600 nm is used. If the wavelength of light is changed to 400 nm, number of fringes observed in the same segment of the screen is given by
12
18
24
30
In the ideal double-slit experiment, when a glass-plate (refractive index 1.5) of thickness t is introduced in the path of one of the interfering beams (wave-length (), the intensity at the position where the central maximum occurred previously remains unchanged. The minimum thickness of the glass-plate is
2(
2( /3
( /3
(