For a medium, refractive indices for violet, red and yellow are 1.62, 1.52 and 1.55 respectively, then dispersive power of medium is ____.
0.65
0.22
0.18
0.02
Two lenses having has combination to make no dispersion. Find the ratio of dispersive power of glasses used ____.
2 : 3
3 : 2
4 : 9
9 : 4
If refractive index of red, violet and yellow lights are 1.42, 1.62 and 1.50 respectively for a medium. Its dispersive power is ____.
0.4
0.3
0.2
0.1
Fraunhofer spectrum is a ____.
line absorption spectrum
band absorption spectrum
line emission spectrum
band emission spectrum
The angle of a prism is 60° and its refractive index is . The angle of minimum deviation suffered by a ray of light in passing through it is ____.
About 20°
30°
60°
45°
Colour of the sky is blue due to ____.
scattering of light
total internal reflection
total emission
None of the above
Which of the following spectrum have all the frequencies from high to low frequency range?
band spectrum
continuous spectrum
line spectrum
discontinuous spectrum
Stars are not visible in the day time because ____.
stars hide behind the sun
stars do not reflect sun rays during day
stars vanish during the day
atmosphere scatters sunlight into a blanket of extreme brightness through which faint stars cannot be visible
Which of the following colours suffers maximum deviation in a prism?
yellow
blue
green
orange
1/2
1/4
2
1/5
The refractive indices for the light of violet and red colours of any material are 1.66 and 1.64 respectively. If the angle of prism made of this material is 10o, then angular dispersion is ____.
0.20o
0.10o
0.40o
1o
The refractive index of the material of the prism for violet colour is 1.69 and that for red is 1.65. If the refractive index for mean colour is 1.66, the dispersive power of the material of the prism ____.
0.66
0.06
0.65
0.69
The deviation caused in red, yellow and violet colours for crown glass prism are 2.84o, 3.28o and 3.72o respectively. The dispersive power of prism material is ____.
0.268
0.368
0.468
0.568
Dispersion of light is due to ____.
wavelength
intensity of light
density of medium
None of the above
A prism of refracting angle 60o is made with a material of refractive index (. For a certain wavelength of light, the angle of minimum deviation is 30o. For this, wavelength the value of refractive index of the material is ___.
1.231
1.820
1.503
1.414
Which of the prism is used to see infrared spectrum of light?
Rock Salt
Nicol
Flint
Crown
When white light enters a prism, it gets split into its constituent colours. This is due to ____.
high density of prism material
because ( is different for different (
diffraction of light
velocity changes for different frequencies
The dispersive powers of crown and flint glasses are 0.02 and 0.04 respectively. In an achromatic combination of lenses the focal length of flint glass lens is 40 cm. The focal length of crown glass lens is ____.
– 20 cm
+ 20 cm
– 10 cm
+ 10 cm
When a ray of light is incident normally on one refracting surface of an equilateral prism (Refractive index of the material of the prism = 1.5 ____.
emerging ray is deviated by 30o
emerging ray is deviated by 45o
emerging ray just grazes the second refracting surface
the ray undergoes total internal reflection at the second refracting surface
Consider the following two statements A and B and identify the correct choice in the given answers ____.
A : Line spectra is due to atoms in gaseous state
B : Band spectra is due to molecules
both A and B are false
a is true and B is false
a is false and B is true
both A and B are true
If the refractive angles of two prisms made of crown glass are 10o and 20o respectively, then the ratio of their colour deviation powers is ____.
1 : 1
2 : 1
4 : 1
1 : 2
The nature of sun’s spectrum is _____.
continuous spectrum with absorption lines
line spectrum
the spectrum of the helium atom
band spectrum
For a prism of refractive index 1.732, the angle of minimum deviation is equal to the angle of the prism. The angle of the prism is ____.
80o
70o
60o
50o
The spectrum obtained from an electric lamp or red hot heater is ____.
line spectrum
band spectrum
absorption spectrum
continuous spectrum