The mixing up of two gases as a result of random motion of molecules is called
diffusion
effusion
vaporisation
sublimation
Correct Answer :
A. diffusion
Related Questions
The cover of a solar cooker is made of glass because
it absorbs sun's rays
it reflects sun's rays
it retains the heat inside by the greenhouse effect
it radiates heat better than metals
Holography is the technique of
taking photos of various objects
recording and reproducing three dimensional images
tracing out planets and stars in the sky
transmitting light waves
The rings of Saturn were discovered by
Galileo
Bhaskara
Aryabhatta
Ptolemy
Light from the sun reaches the earth in
2 minutes
4 minutes
12 minutes
8 minutes
Halley's comet appears in the heavens once in
40 years
50 years
76 years
80 years
When the earth reaches its perihelion
it is nearest to the moon
it is nearest to the sun
it is nearest to Pluto
it is farthest from the sun
A radio set that uses valves does not start operating immediately when it is switched on whereas a set containing only tranaistors operates immediately. The reason for this is that
the valve filaments have low resistance
valve-radio sets work at a higher voltage
transistor set has a low resistance
filaments of the valves cake time to beat up and function
For detecting and, testing of small electric charges we use
an electrophorus
an electroscope
an electromagnet
an ammeter
Ultrasonic waves are used
in medical and surgical diagnosis
in testing the quality of the linings and pads used in vehicles and aircraft brakes
to clean surgical instruments, jewellery and similar articles
All the above
The fact that two large ships travelling on close parallel courses in the same direction tend to move towards each other can be explained by
Bernoulli's principle
Magnetic properties of the ship's material
Newton's third law of motion
Earth's gravitational force
Which of the following rays has the highest penetrative power?
�± -rays
�² -rays
�³ -rays
X-rays
The difference between planets and stars is
planets do not have light of their own whereas stars shine by their own light
planets do not twinkle like stars
planets are much smaller than stars
All the above
The speed of sound in air at 0° C is approximately
4 x 108 m/s
1500 m/s
330 m/s
500 m/s
The aneroid barometer uses
mercury
distilled water
alcohol
does not use any liquid
The Cact that the compass needle does not point true north was observed first by
Sir Isaac Newton
Columbus
Archimedes
Thomas Alva Edison
A proton is
the ionised hydrogen molecule
the nucleus of helium atom
the nucleus of hydrogen atom
the positive counterpart of electron
Red Light is used as a dancer signal because
it is pleasing to the eye
it has a traditional colour
it is easily distinguishable
it is most sensitive to the human eye
The first Indian Satellite launched from a Russian Cosmodrome on April 16, 1975 was named
Bhaskara
Insat I-A
Aryabhatta
SLV-l
The number of galaxies that are visible without telescope on clear dark nights and away from bright lights is
one
two
three
infinite
A bar magnet tied in the middle with a thread is suspended at the South Pole of the earth. The magnet will be in
a horizontal position
a nearly vertical position with its South Pole downwards
a nearly vertical position with its North Pole downwards
a slanting position
The velocity of sound in air increases with
the rise of temperature
rise of its frequency
decrease in humidity
fall of temperature
Lightning conductors are made of
iron
chromium
copper
steel
Ultrasonic waves are used
in medical and surgical diagnosis
in testing the quality of the linings and pads used in vehicles and aircraft brakes
to clean surgical instruments, jewellery and similar articles
All the above
Bats flying in the dark avoid obstacles because
they can see very dearly only in darkness
they produce ultrasonic waves which guide them
their eyes are sensitive to darkness
their eye holes expand in darkness
Mercury does not stick to glass because
cohesive forces between the mercury molecules are greater than adhesive forces between mercury and glass molecules
the adhesive forces between mercury and glass molecules are greater than the cohesive forces
both the cohesive and adhesive forces are equal
None of the above
Sound waves
are electromagnetic waves
can easily pass through vacuum
are always transverse waves
require a material medium for propagation
When a charged rod is brought near a collection of small pith balls, the balls
will jump rapidly up and down for a short time
will remain unaffected
Both (a) and (b) above
It will produce electric shock
If a body is taken from the earth to the moon
both its mass and weight will be different
its mass will be different but the weight will remain the same
its mass and weight will both remain unchanged
its mass will remain the same but weight will be different
The principle of equivalence of mass and energy was established by
Dalton
Rutherford
Einstein
Planck
The transistor was invented by
Marconi
Baird
John Bardeen, Walter H. Brattain and William Shockley
Edison