Which source is associated with a line emission spectrum?
Electric fire
Neon street sign
Red traffic light
Sun
The critical angle between an equilateral prism and air is 45°. If the incident ray is perpendicular to the refracting surface, then _____.
after deviation it will emerge from the second refracting surface
it is totally reflected on the second surface and emerges out perpendicularly from third surface in air
it is totally reflected from the second and third refracting surfaces and finally emerges out from the first surface
it is totally reflected from all the three sides of prism and never emerges out
When white light passes through a glass prism, one gets spectrum on the other side of the prism. In the emergent beam, the ray which is deviating least is or
Deviation by a prism is lowest for ____.
violet ray
green ray
red ray
yellow ray
We use flint glass prism to disperse polychromatic light because light of different colours ____.
travel with same speed
travel with same speed but deviate differently due to the shape of the prism
have different anisotropic properties while traveling through the prism
travel with different speeds
A prism has the refracting angle of 30°. The deviation of a monochromatic ray incident normally on its one surface is (sin 48° 36’ = 0.75) ____.
18° 36’
20° 30’
18°
22°1’
Fraunhofer lines are obtained in ____.
solar spectrum
the spectrum obtained from neon lamp
spectrum from a discharge tube
None of the above
When light rays are incident on a prism at an angle of 45°, the minimum deviation is obtained. If refractive index of the material of prism is , then the angle of prism is ____.
30°
40°
50°
60°
Light from sodium lamp is passed through cold sodium vapors, the spectrum of transmitted light consists of ____.
a line at 5890 Å
a line at 5896 Å
sodium doublet lines
No spectral features
Angle of minimum deviation for a prism of refractive index 1.5 is equal to the angle of prism. The angle of prism is (cos 41° = 0.75) ____.
62°
41°
82°
31°
In the formation of primary rainbow, the sunlight rays emerge at minimum deviation from rain-drop after ____.
one internal reflection and one refraction
one internal reflection and two refractions
two internal reflections and one refraction
two internal reflections and two refractions
Dispersive power depends upon ____.
the shape of prism
material of prism
angle of prism
height of the prism
When white light passes through the achromatic combination of prisms, then what is observed?
Only deviation
Only dispersion
Deviation and dispersion
None of the above
The dispersion for a medium of wavelength ( is D, then the dispersion for the wavelength 2( is ____.
D
The ratio of angle of minimum deviation of a prism in air and when dipped in water is ( and) ____.
The number of wavelengths in the visible spectrum _____.
4000
6000
2000
Infinite
The black lines in the solar spectrum during solar eclipse can be explained
by ____.
Planck's law
Kirchoff's law
Boltzmann's law
Solar disturbances
The dispersive power is maximum for the material ____.
flint glass
crown glass
mixture of both
None of the above
A light ray is incident by grazing one of the face of a prism and after refraction ray does not emerge out, what should be the angle of prism while critical angle is C?
equal to 2C
less than 2C
more than 2C
None of the above