In Young's double slit experiment, a third slit is made in between the double slits. Then
intensity of fringes totally disappears
only bright light is observed on the screen
fringes of unequal width are formed
contrast between bright and dark fringes is reduced
D.
contrast between bright and dark fringes is reduced
If a third slit is made between the double slits, then contrast between bright and dark fringes is reduced.
In a two slit experiment with monochromatic light fringes are obtained on a screen placed at some distance from the slits. If the screen is moved by 5 x 10-2 m towards the slits, the change in fringe width is 3 x 10-5 m. If separation between the slits is 10-3 m, the wavelength of light used is
In a Fraunhofer diffraction experiment at a single slit using a light of wavelength 400 nm, the first minimum is formed at an angle of 30°. The direction θ of the first secondary maximum is given by
Maximum diffraction takes place in a given slit for
γ-rays
ultraviolet rays
infrared light
radiowaves
An unpolarised beam of intensity I0 falls on a polaroid. The intensity of the emergent light is
I0
Zero
For the constructive interference the path difference between the two interfering waves must be equal to
(2n + 1) λ
2nπ
nλ
G P Thomson experimentally confirmed the existence of matter waves by the phenomena
diffraction
refraction
polarisation
scattering
Young's double slit experiment gives interference fringes of width 0.3 mm. A thin glass plate made of material of refractive index 1.5 is kept in the path oflight from one of the slits, then the fringe width becomes
zero
0.3 mm
0.45 mm
0.15 mm
Red light of wavelength 625 nm is incident normally on an optical diffraction grating with 2 × 105 lines/m. Including central principal maxima, how many maxima may be observed on a screen which is far from the grating?
15
17
8
16