The attraction of unlike molecules at the common surface is known as
adhesion
cohesion
surface tension
capillarity
Correct Answer :
A. adhesion
Related Questions
Skating on ice is possible because
the surface of ice is smooth
ice is cold
the pressure on the ice due to skate melts the ice by lowering its melting point forming a thin film of water
the pressure on the ice due to skate raises its melting point
In very cold countries alcohol is used as a thermometric liquid because
alcohol is a poor conductor of heat
alcohol can be coloured for its level to be seen easily
its freezing point is very low
it will not stick to the glass tube
For accurate scientific work, temperatures are often measured by
mercury thermometers
alcohol thermometers
platinum resistance thermometers
thermoelectric thermometers
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
The planet that is known as earth's twin is
Mercury
Venus
Moon
Mars
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
A piece of ice is Boating In water kept in a beaker. When all the ice melts the level of water will
first rise and then fall
fall
remain the same
rise
The resistance of a wire depends on
the material of the wire
the length of the wire
the cross section of the wire
All the above
At what temperature do the Fahrenheit and Kelvin scales give the same reading?
212°
32°
-40°
0°
Frictional force acts in
the same direction as the motion
the opposite direction of the motion
all the directions
upward direction
When an electric apparatus is fitted with a three core flexible lead the insulation on the three wires is distinctively coloured. The present international convention is
brown for earth, yellow for live, light blue for neutral
green for earth, yellow for live, brown for neutral
yellow for earth, green for live, brown for neutral
brown or red for live, light blue or black for neutral and green or yellow for earth
In hot climatic conditions, the buildings are painted white because
white paint is economical
it does not fade off
it does not crack with higher temperature
white coating is a bad conductor of heat and reflects heat rays that fall on it, thus keeping the inside cool
Before the invention of geostationary satellites, television stations could not transmit their programmes to far off places because
these signals are electromagnetic in nature
these are not electromagnetic in nature
their wavelength is very large
they are not reflected by the ionosphere but pass through it
In experiments on static electricity the standard method for obtaining small amounts of positive electricity is to rub
a glass rod with flannel
an abonite rod with flannel
a glass rod with silk
Any of the above
Resistance is measured in
Volts
Amperes
ohms
coulombs
The number of electrons in the outer orbits of a nucleus gives
the mass number
atomic number
atomic weight
absolute number
Compared to the atomic bomb, the destructive power of a hydrogen bomb is
greater
less
equal
can't be determined
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
The following are the atmospheric zones above the surface of the earth:
A) Troposphere
B) Ionosphere
C) Stratosphere
D) Exosphere
Select the correct sequence from the earth's surface on the basis of the codes given below:
ACBD
ABCD
CABD
BACD
Moon has no atmosphere because
it has no population
it is quite far off
its surface is full of rocks
its gravity is not sufficient for any atmosphere to hold on to it
A hunter on the ground wishes to shoot a bird on a tree at a distance with his rifle. He has to point the rifle
at the lower elevation than the bird
at a higher elevation than the bird
in the same direction as the bird
vertically upwards
Which mirror is used as a rear view mirror in Vehicles?
Parabolic
Convex
Concave
Plain
The phenomenon of spontaneous disintegration of certain heavy nuclei is termed
radioactivity
fission
fusion
implosion
The best estimates of the age of the earth comes from the studies of
angle of inclination of the earth
changes in radio-active minerals in it
period taken by Sun's light to reach the earth
artificial satellites revolving round the earth
The motion .of the pendulum of a wall clock is an example of
linear motion
vibratory motion
rotational motion
None of the above
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 light from the star nearest to the sun reaches the earth in
8 minutes
4.3 years
12 seconds
24 hours
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 base of an electric iron is brightly polished mainly
to make it smooth and frictionless
to make it rust - proof
to reduce heat loss by radiation
to make it more durable
The force of attraction or repulsion between two charged bodies is directly proportional to the product of the charges and inversely proportional to the square of distance between them. This was propounded by
Coulomb
Gilbert
Volta
Rutherford