21.
Twinkling of stars and non-twinkling of planets is accounted for by
A
scattering of light
B
dispersion of light
C
atmospheric refraction
D
none of these
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Twinkling of stars and non-twinkling of planets is accounted for by
scattering of light
dispersion of light
atmospheric refraction
none of these
To an astronaut in a spaceship, the colour of earth appears
red
blue
white
black
The velocity of waves of all colours is same in:
water
oxygen
vaccum
glass
The sun appears oval shaped or flattened due to
dispersion
scattering
atmospheric refraction
cannot say
The stars twinkle, while the planets do not. Why?
Closer planets are not point sources but due to long distance stars appear as point sources
Stars have ability light fragments while planets transmit light continuously
Light from star travel faster than planets
None of these
The star appear shifted from their actual position due to the phenomenon of
Diffraction of light
Scattering of light
Refraction of light
Reflection of light
The splitting of white light into its component colours is called
refraction
reflation
dispersion
Tyndall effect
The refractive index assumes the entrance of light from
glass
water
vacuum
gas
The phenomenon of scattering of light by the colloidal particles is called
Dispersion of light
Tyndall effect
Atmospheric scattering
Atmospheric refraction
The phenomena that play a role in the formation of rainbow is:
reflection and refraction of light
refraction, absorption, dispersion and refraction of light
dispersion, refraction and reflection of light
Refraction, dispersion, reflection and refraction of light.
The effect of glass prism is only to separate the seven colours of
White light
light from bulb
Sunlight
All of the above
The dispersive power of prism depends upon
The shape of the prism
The material of the prism
The angle of the prism
Height of the prism
The danger signs made red in colour, because
the red light can be seen from farthest distance
the scattering of red light is least
both a and b
none of these
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light
is scattered the most by smoke or fog.
is scattered the least by smoke or fog.
is absorbed the most by smoke or fog.
moves fastest in air.
The colour of sky appears blue, it is due to the
refraction of light through the atmosphere
dispersion of light by air molecules
scattering of light by air molecules
all of these
The colour of a star is an indication of its
weight
distance
temperature
size
The clear sky appears blue because
blue light gets absorbed in the atmosphere.
ultraviolet radiations are absorbed in the atmosphere.
violet and blue lights get scattered more than lights of all other colours by the atmosphere.
light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.
The bluish colour of water in deep sea is due to
the presence of algae and other plants found in water
reflection of sky in water
scattering of light
absorption of light by the sea
The blue colour of the sky is because
red colour is scattered more as compared to other colours.
red colour is absorbed more as compared to other colours
blue colour is scattered more as ccompared to other colours
blue colour is absorbed more as compared to other colours
The air layer of atmosphere whose temperature is less than the hot layer behave as optically
denser medium
rarer medium
inactive medium
either denser or rarer medium