When a bottle of perfume la 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
Every action has an equal and opposite reaction is Newton's law of Motion
first
second
third
fourth
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
Which of the following is fissionable?
U-234
U-235
U-238
Both (b) and (c)
A sensitive instrument susceptible to magnetic infiuence can be protected from external magnetic field by
enclosing it in a thick walled iron box
wrapping it with an insulator
by placing it inside a glass case
by surrounding it with fine copper gauze
Air pressure is usually highest when the air is
warm and moist
cool and dry
warm and dry
cool and moist
The velocity required to place a vehicle in orbit round the moon is _________ that required to place it in orbit round the earth.
less than
greater than
equal to
greater than or equal to
The filament used in the electric lamp is made of
nichrome
tungsten
copper
aluminium
The device that is used to measure the electromotive force of a cell is
an ammeter
a rheostat
a voltmeter
a voltameter
The extremely luminous objects located at the centre of some distant galaxies and which are sources of high energy electromagnetic radiation are known as
Nebulae
Quasars
Meteors
Comets
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
When sound waves travel from one medium to another, the quantity which remains unchanged is its
speed
frequency
wavelength
All the above
It is difficult to bon potatoes at the top or a mountain because
the water available is hard
it is colder than at sea level
the potatoes become hard
the boiling point of water is lower at that height on account of low atmospheric pressure
Diamond shines because of its
purity
hardness
high density
high refractive index and low critical angle
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
For viewing objects placed at a higher level from a position at a lower level, the instrument used' Is known aa
telescope
spectrometer
microscope
periscope
In a vacuum the following three articles are dropped at the same time and from the lame height. Which will reach the ground quicker?
a stone
a piece of wood
a feather
all will reach the ground at the same time
The air inside an electric, bulb is removed to prevent
oxidation of the tungsten filament
bursting of the bulb
loss of light due to absorption
keeping the weight of the bulb less
The principle of equivalence of mass and energy was established by
Dalton
Rutherford
Einstein
Planck
The asteroids belt lies between the orbits of
Earth and Mars
Venus and Earth
Mars and Jupiter
Moon and Mars
Body A is kept in contact with body B. Heat will flow from A to B if
the heat content of A is greater than that of B
the temperature of A is greater than that of B
the specific heat of A is greater than that of B
the specific heat of B is greater than that of A
Sound waves
are electromagnetic waves
can easily pass through vacuum
are always transverse waves
require a material medium for propagation
A projectile is fired at an angle with the horizontal with a small velocity. Its horizontal range will be maximum when the angle with the horizontal is
0°
30°
45°
60°
The period of a geostationary (synchronous) satellite orbiting the earth over the equator la
16 hours
12 hours
20 hours
24 hours
The barometer was invented by
Michael Faraday
Torricelli
Thomas Alva Edison
Benjamin Franklin
For an electron orbiting in a hydrogen atom, the necessary centripetal force keeping it in orbit is provided by
the electrical attraction between the negatively charged electron and the positively charged porton
the high speed of the electron
the low speed of the electron
gravity
Nuclear fusion is a process in which
the atoms and molecules lose their identity
nucleus is split into fragments
the nuclear reaction between two light atomic nuclei results in the formation of a heavier nucleus with release of a large quantity of nuclear energy in the process
absorption of neutron by a nucleus
Fish and other aquatic creatures can live inside a deep frozen pond because
fish are cold-blooded animals
ice is a bad conductor of heat
there will always be water just beneath the ice level
they can adapt themselves to live in ice
The device for tracking and locating the position of a moving object in space is called
Space ship
Lunar module
Radar
Rocket
The stars that shine brightly then dimly and then brightly are known as
meteors
binaries
variable stars
bright stars
Fish and other aquatic creatures can live inside a deep frozen pond because
fish are cold-blooded animals
ice is a bad conductor of heat
there will always be water just beneath the ice level
they can adapt themselves to live in ice