Angle of prism is A and its one surface is silvered. Light rays falling at an angle of incidence 2A on first surface return back through the same path after suffering reflection at second silvered surface. Refractive index of the material of prism is ____.
2 sin A
2 cosA
When seen in green light, the saffron and green portions of our National Flag will appear to be ____.
black
black and green respectively
green
green and yellow respectively
At sun rise or sunset, the sun looks more red than at mid-day because ____.
the sun is hottest at these times
of the scattering of light
of the effects of refraction
of the effects of diffraction
Line spectrum contains information about ____.
the atoms of the prism
the atoms of the source
the molecules of the source
the atoms as well as molecules of the source
Missing lines in a continuous spectrum reveal ____.
defects of the observing instrument
absence of some elements in the light source
presence in the light source of hot vapour of some elements
presence of cool vapour of some elements around the light source
A source emits light of wavelength 4700Å, 5400 Å and 6500 Å. The light passes through red glass before being tested by a spectrometer. Which wavelength is seen in the spectrum?
6500 Å
5400 Å
4700 Å
All of the above
A ray passes through a prism of angle 60° in minimum deviation position and suffers a deviation of 30°. What is the angle of incidence on the prism?
30°
45°
60°
90°
When light of wavelength is incident on an equilateral prism kept in its minimum deviation position, it is found that the angle of deviation equals the angle of the prism itself. The refractive index of the material of the prism for the wavelength is, then ____.
2
A neon sign does not produce ____.
line spectrum
an emission spectrum
an absorption spectrum
photons
The refractive index of flint glass for blue F line is 1.6333 and red C line is 1.6161. If the refractive index for yellow D line is 1.622, the dispersive power of the glass is ____.
0.0276
0.276
2.76
0.106
The wavelength of emission line spectrum and absorption line spectrum of a substance are related as ____.
absorption has larger value
absorption has smaller value
They are equal
no relation
White light is passed through a prism whose angle is 5°. If the refractive indices for rays of red and blue colour are respectively 1.64 and 1.66, the angle of deviation between the two colours is ____.
0.1 degree
0.2 degree
0.3 degree
0.4 degree
From which source a continuous emission spectrum and a line absorption spectrum are simultaneously obtained?
Bunsen burner flame
the sun
tube light
hot filament of an electric bulb
A thin prism with angle 6° and made from glass of refractive index 1.54 is combined with another thin prism P2 of refractive index 1.72 to produce dispersion without deviation. The angle of prism is ____.
5° 24’
4° 30’
6°
8°
If the refractive index of a material of equilateral prism is , then angle of minimum deviation of the prism is ____.
30°
45°
60°
75°
The splitting of white light into several colours on passing through a glass prism is due to ____.
refraction
reflection
interference
diffraction
A white screen illuminated by green and red light appears to be ____.
green
red
yellow
white
Dark lines on solar spectrum are due to ____.
lack of certain elements
black body radiation
absorption of certain wavelengths by outer layers
scattering
Line spectra are due to ____.
hot solids
atoms in gaseous state
molecules in gaseous state
liquid at low temperature
The path of a refracted ray of light in a prism is parallel to the base of the prism only when the ____.
light is of a particular wavelength
ray is incident normally at one face
ray undergoes minimum deviation
prism is made of a particular type of glass