To observed diffraction, the size of the obstacle
should be much larger than the wavelength
has no relation to wavelength
should be of the order of wavelength
should be where λ is the wavelength
In Young's double slit experiment, the source is white light. One slit is covered with red filter and the other with blue filter. There shall be
alternate red and blue fringes
alternate dark and pink fringes
alternate dark and yellow fringes
no interference
Light of wavelength 600 nm is incident normally on a slit of width 0.2 mm. The angular width of central maxima in the diffraction pattern is (measured from minimum to minimum)
6 × 10-3 rad
4 × 10-3 rad
2.4 × 10-3 rad
4.5 × 10-3 rad
According to Huygens' principle, during refraction of light from air to a denser medium
Wavelength decreases but speed increases
Wavelength increases but speed decreases
Wavelength and speed increases
Wavelength and speed decreases
In a system of two crossed polarisers, it is found that the intensity of light from the second polariser is half from that of first polariser. The angle between their pass axes is
60°
30°
0°
45°
In Young's double-slit experiment, if yellow light is replaced by blue light, the interference fringes becomes
darker
brighter
wider
narrower
D.
narrower
The wavelength (λ) of yellow light is greater than blue light.
We know that,
Here, λ decreases. Hence, the interference fringes becomes narrower.
When one of the slits of Young's experiment is covered with a transparent sheet of thickness 4·8 mm, the central shifts to a position originally occupies by the 30th bright fringe. What should be the thickness of the sheet if the central fringe has to shift to the position occupied by 20th bright fringe ?
1.6 mm
3.8 mm
3.2 mm
7.6 mm
In Young's double slit experiment, the central bright fringe can be identified
as it is narrower than other bright fringes
by using white light instead of monochromatic light
as it has a greater intensity than other bright fringes
as it is wider than other bright fringes
The intensity at the maximum in a Young's double slit experiment is Io. Distance between two slits is d = , where is the wavelength of light used in the experiment. What will be the intensity infront of one of the slits on the screen placed at a distance D = 10 d?
3
A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 m/s. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is (Take, velocity of sound in air = 330 m/s)
800 Hz
838 Hz
885 Hz
885 Hz