When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of
surface tension
capillarity
viscosity
diffusion
Correct Answer :
D. diffusion
Related Questions
The Cact that the compass needle does not point true north was observed first by
Sir Isaac Newton
Columbus
Archimedes
Thomas Alva Edison
A spherical mirror is
a reflecting elliptical portion
a reflecting spherical surface
a parabolic reflecting surface
a flat reflecting surface
The largest planet in the solar system is
Neptune
Uranus
Jupiter
Saturn
A wire conveying a current deflects a pivoted magnetic needle. This was discovered by
Marconi
Oersted
Faraday
Ohm
A ship sailing from a river to the sea
sinks less in the sea
sinks more in the sea
neither sinks more nor less in the sea
sinking more or less depends on sea
A solar eclipse occurs when the earth, the sun and the moon are in a straight line, and
when the moon passes between the sun and the earth
when the sun comes between the earth and the moon
when the earth comes between the sun and the moon
on a full moon day
The stars that shine brightly then dimly and then brightly are known as
meteors
binaries
variable stars
bright stars
When a particle in motion is acted upon by a force in a direction perpendicular to the direction of motion, the path followed by the particle will be
a straight line
an ellipse
a circle
a parabola
The temperature, surface features, length of days and nights of a planet depend on
its atmosphere
its distance from the sun
its rotation
All the above
Which mirror is used as a rear view mirror in Vehicles?
Parabolic
Convex
Concave
Plain
The mirage is a phenomenon
generally considered as a desert happening
caused by unequal heating of the several layers of the atmosphere above the desert
in which the refracted rays take a curved path resulting in total internal refection
All the above
Halley's comet appears in the heavens once in
40 years
50 years
76 years
80 years
If the speed of the rotation of the earth increases the weight of a body
will increase
will decrease
will have no change
will either increase or decrease
A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance
will increase
will decrease
does not change
varies with the increase of depth of the immersion of the iron piece
In an electrical circuit, a fuse is connected
in the live wire
in the neutral wire
in the earth wire
anywhere
Sound waves
are electromagnetic waves
can easily pass through vacuum
are always transverse waves
require a material medium for propagation
An electric kettle used for boiling hard water has a white scale deposited on its heating element. This consists or
sugar
sodium carbonate
common salt
carbonates of calcium and magnesium
A lightning conductor installed in a building
does not allow the lightning to fall on the building at all
drives away the charged clouds
forces the lightning to fall on other buildings near that building
conducts the electric charges to the ground when lightning strikes the building
In a dynamo
mechanical energy is converted to light energy
mechanical energy is converted to heat energy
mechanical energy is converted to electrical energy
electrical energy is converted to mechanical energy
The freezer in a refrigerator is placed near the top
to keep it away from the hot compressor which is near the bottom
because of convenience
so that it can cool the whole interior by setting up convection currents
to prevent too much cooling
A small bubble of air deep down in a lake rises up to the top of the lake. The volume of the bubble on coming up will
increase
decrease
will not change
first increase and then decrease
Hot water is poured simultaneously in four metallic tumblers painted outside with different paints. After some time the water will be found to have cooled most in the tumbler painted.
rough white
rough black
shining white
shining black
Cyclotron is an apparatus used
as an accelerator for imparting energies to charged particles of atomic magnitudes
to reduce the charge on a particle
to produce intense magnetic field
to produce intense electrical field
It is easier to climb down a staircase than climb up because in climbing down
work is done against gravity
the steepness of the staircase isn't felt
gravity assists
there is no friction between the legs and steps
A hydrogen bomb is based on
nuclear fusion
nuclear fission
Both (a) and (b) above
Neither (a) nor (b)
The focal length or lens or the eye is under the control or the
iris
pupil
ciliary body
cornea
The weight of a body is
maximum at the equator
minimum at the equator
minimum at the poles
the same everywhere
The mode of travel of heat energy from the sun across the empty space beyond the earth's atmosphere is known as
conduction
convection
radiation
absorption
On the Kelvin scale, the melting point of ice is
0 K
273 K
373 K
100 K
The phenomenon of spontaneous disintegration of certain heavy nuclei is termed
radioactivity
fission
fusion
implosion