1. The scattering of light by
colloidal solution is called-
(a) Tyndall effect
(b) Raman effect
(c) Colloidal effect
(d) Refraction effect
ANS: Tyndall effect
2. Which phenomenon is responsible
for making the path of light visible?
(a) Tyndall effect
(b) Total internal refraction
effect
(c) Colloidal effect
(d) Refraction effect
ANS: Tyndall effect
3.
Which of the following is not an example of Tyndall effect?
(a) When a fine beam of light
enters a smoke filled dark room through a small hole
(b) Twinkling of stars
(c) When sunlight passes through
a canopy of dense forest in misty conditions.
(d) Shinning a beam of
flashlight into the glass of milk
ANS: Twinkling of stars
4. The colour of the scattered
light depends on ____ of the scattering particles.
(a) colour
(b) speed
(c) size
(d) number
ANS: size
5.
Fine particles mostly scatter ______.
(a) shorter wavelength such as
blue
(b) longer wavelength such as blue
(c) shorter wavelength such as
red
(d) longer wavelength such as
red
ANS: shorter wavelength such as blue
6. Large size particles mostly
scatter-
(a) shorter wavelength such as
blue
(b) longer wavelength such as
blue
(c) shorter wavelength such as
red
(d) longer wavelength such as
red
ANS: longer wavelength such as red
7. The main reason behind the phenomenon
of scattering of light is,
(a) light has large wavelength
value of the order of few metres
(b) light wave can travel
through vacuum
(c) light waves are deflected by
fine particles, molecules present in the air
(d) Sun light is composite light
with blue as its major constituent
ANS: Light waves are deflected by fine
particles, molecules present in the air
8. If size of particles is
comparable to wavelengths of incident light then,
(a) scattering does not take place
(b) all wavelengths will get
scattered equally
(c) scattered light appears violet
(d) internal reflection takes
place
ANS: all wavelengths will get
scattered equally
9. The blue colour of the sky is
due to-
(a) refraction of light
(b) dispersion of light
(c) scattering of light
(d) internal reflection of light
ANS: scattering of light
10.
The clear sky appears blue because,
(a) blue light gets absorbed in
the atmosphere
(b) ultraviolet radiations are
absorbed in the atmosphere
(c) violet and blue lights get
scattered more than lights of all other colours by the atmosphere
(d) light of all other colours
is scattered more than the violet and blue colour lights by the atmosphere
ANS: violet and blue lights get
scattered more than lights of all other colours by the atmosphere
11. Though violet colour gets
scattered more than blue, sky appears blue instead of violet. This is because-
(a) violet is not a primary
colour
(b) violet colour has greater
wavelength than blue colour
(c) our eyes are more sensitive
to blue as compared to violet
(d) all the above
ANS: our eyes are more sensitive to
blue as compared to violet
12. The appearance of sky in
large industrial cities is different from the villages because-
(a) presence of minute particles
in large quantity in the atmosphere than in village
(b) cities are situated at
higher sea level
(c) electromagnetic signals are constantly
telecasted over city sky
(d) presence of minute particles
in small quantity in the atmosphere than in village
ANS: presence of minute particles in
large quantity in the atmosphere than in village
13. If the earth had no
atmosphere then the sky would have appeared-
(a) blue
(b) red
(c) bright
(d) dark
ANS: dark
14. The sky appears dark to
passengers flying at very high altitudes mainly because
(a) scattering of light is not
enough at such heights
(b) there is no atmosphere at
great heights
(c) the size of molecules is
smaller than the wavelength of visible light
(d) the light gets scattered towards
the earth
ANS: there is no atmosphere at great
heights
15.
The colour of the sky as seen from the moon is
(a) blue
(b) white
(c) dark
(d) cyan
ANS: dark
16. Clouds usually appear white
because of-
(a) scattering of light
(b) internal reflection of light
(c) fluctuating refractive index
of atmosphere
(d) absorption of light
ANS: scattering of light
17.
The bluish colour of water in deep sea is due to-
(a) the presence of algae and
other plants found in water
(b) reflection of sky in water
(c) scattering of light
(d) absorption of light by the
sea
ANS: scattering of light
18. One cannot see through fog,
because-
(a) fog absorbs light
(b) the refractive index of fog
is infinity
(c) light suffers internal
reflection at the droplets in fog completely
(d) light is scattered by the
droplets in fog
ANS: light is scattered by the
droplets in fog
19.
As red light is scattered the ____ by atmosphere, it can travel ____
distance.
(a) most, smaller
(b) most, larger
(c) least, smaller
(d) least, larger
ANS: least, larger
20. 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-
(a) is scattered the most by
smoke or fog
(b) is scattered the least by
smoke or fog
(c) is absorbed the most by
smoke or fog
(d) moves fastest in air
ANS: is scattered the least by smoke
or fog
21. The Sun appears reddish or
orange reddish at the-
(a) sunset
(b) mid-day
(c) sunrise
(d) both (A) and (C)
ANS: both (A) and (C)
22.
Which of the following phenomena contributes significantly to the
reddish appearance of the sun at sunrise and sunset?
(a) dispersion of light
(b) scattering of light
(c) total internal reflection of
light
(d) reflection of light from the
earth
ANS: scattering of light
23. When the Sun is near the
horizon,
(a) no wavelength reach our eyes
(b) only shorter wavelength reach
our eyes
(c) only longer wavelength reach
our eyes
(d) scattering does not take
place
ANS: only longer wavelength reach our
eyes
24. Just after the sunrise, the
sunlight has to travel-
(a) longer path through the
atmosphere to reach the observer
(b) shorter path through the
atmosphere to reach the observer
(c) through dew drops formed by
dawn
(d) through atmospheric layers
with constant refractive index
ANS: longer path through the
atmosphere to reach the observer
25. The red colour of the sun at
the time of sunrise and sunset is because-
(a) red colour is most scattered
(b) blue colour is least scattered
(c) red colour is least
scattered
(d) blue colour is most
scattered
ANS: red colour is least scattered
26.
At noon the Sun appears white as-
(a) light is least scattered
(b) all the colours of the white
light are scattered away
(c) blue colour is scattered the
most
(d) red colour is scattered the
most
ANS: light is least scattered
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