Separating particles from a suspension is effected by
centrifugal force
frictional force
gravitational force
distillation
Correct Answer :
A. centrifugal force
Related Questions
Increase in pressure
increases the melting point of ice
decreases the melting point of ice
has no effect on the melting point of ice
increases the volume of the ice
The colour or an opaque object is due to the colour it
absorbs
refracts
reflects
scatters
An astronomical unit of distance is
a kilometre
light year
the average distance from the earth to the sun
None of the above
The acoustical quality of a room depends on
the size and shape of the room
the ability of the ceiling, walls and floor to exclude unwanted sound
the use of furnishings made of sound absorbing materials
All the above
Rain drops acquire spherical shape due to
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friction
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The attraction of unlike molecules at the common surface is known as
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cohesion
surface tension
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The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because
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the glass of the bell jar absorbs the sound waves
the bell jar is too small
there is no air or -any other gas in the bell jar
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for measuring relative density of liquids
by ships to pass on messages
for determining the depth of ocean bottoms etc.
by deaf people to aid hearing
Meteors
look like falling stars
are really pieces of rock or metal
burn up as they shoot through the air
All the above
Thick brick walls are used in the construction or a cold storage because bricks
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are cheaper
are easily obtained
are bad conductors of heat
Pieces of camphor placed on water move about rapidly. This is because of
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The filament lamp is an example for
fluorescence
incandescence
both (a) and (b)
None of these
Which of the following apparatus is used in the electrolysis of water?
Voltmeter
Voltameter
Ammeter
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Solar radiation is preferred to other sources of energy because
it is practically inexhaustible
it is the cheapest form of energy
it does not cause pollution
All of the above
Formation of shadows can be explained by
rectilinear propagation of light
reflection
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total internal reflection
A bolometer is used to measure
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thermal radiations quantitatively
high temperature
the intensity of sound
The frequency of an ultrasonic wave is
the same as that of an audible sound
above the audible range
below the audible range
None of the above
In the nucleus of an atom, the uncharged particle is
proton
neutron
electron
positron
It is more difficult to walk on ice than on a concrete road because
there is very little friction between the ice and feet pressing it
ice is soft when compared to concrete
there is more friction between the ice and feet
None of the above
Which force is used when milk is churned to separate cream?
cohesive
centrifugal
frictional
gravitational
Echoes are produced by
the reflection of sound waves
the refraction of sound waves
the interference of sound waves
reverberation of sound waves
The principle on which a Jet engine works is
conservation of mass
Newtonian law of action and reaction
conservation of angular momentum
None of the above
When a body is projected upwards
the time for the upward journey and downward journey are the same
the upward journey takes more time
the downward journey takes more time
Can't be said
The Solar System lies near the edge of a galaxy known as
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Radio Galaxy
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We always see only one side of the moon because
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the time taken by the moon to rotate on its axis is the same as the time taken by it to revolve round the earth
moon revolves round the sun
When light passes from air to glass, its velocity in glass
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decreases
remains unchanged
first decreases then increases
When an incident beam of light strikes the surface of a glass slab normally, the refracted beam
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gets deviated away from the normal
gets bent towards the normal
gets reflected
A person cups his hand around the mouth when shouting. Why?
Sound energy from his mouth is then directed in one direction
The cupped hand acts as a cardboard tube of short length
The pitch of sound increases
Both (a) and (b)
The body of an electrical appliance is earthed in order that
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there may be smooth flow of electricity
a short circuit may be prevented
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The colour of the light which travels through glass with minimum speed is
red
violet
green
yellow