Which of the following is known as freon?
Liquid ammonia
Carbon tetrafluoride
Dichloro-difluoro-methane
Sulphur dioxide
Correct Answer :
C. Dichloro-difluoro-methane
Related Questions
Photocells are used
in burglar alarms
in automotive devices for light switches
television cameras
All the above
In a longitudinal wave, the direction of propagation of the wave is
the same as the direction of the vibrations of the vibrating body
at right angles to the direction of the vibrations of the vibrating body
Both (a) and (b) above
None of the above
The numerical reading of the Fahrenheit thermometer of a given temperature
is proportional to that of the Celsius thermometer
is always greater than that of the Celsius thermometer
is always less than that of the Celsius thermometer
may be greater than or less than or equal to that of the Celsius thermometer
Air escaping rapidly from a narrow orifice in an inflated tyre feels cool because
the speed with which it escapes cools it down
of the higher temperature of the surroundings
of sudden expansion causing loss of internal energy
there is no real fall in temperature
The stem of a vibrating tuning fork is pressed against a sound box. Then
the loudness of the sound increases
the loudness remains the same
the loudness decreases
the sound suddenly stops
A rod of brass is held in hand and rubbed with fur. The rod is found to have
no charge
positive charge
negative charge
can't be said
Which of the following revolves round the nucleus in an atom?
protons
electrons
neutrons
positrons
A light year means
a unit of time
a unit of length
a year of no consequence
illumination throughout the year
Tea pots are highly polished
so that they may reflect thermal radiation from outside and minimise such radiation from them
so that they may absorb all radiation from outside
to make them attractive to look at
because they take high polish
The enormous energy released in nuclear and thermonuclear reactions is due to conversion of
chemical energy into heat energy
mechanical energy into heat energy
protons into neutrons
mass into energy according to Einstein's equation
Why is nuclear fusion also known as thermonuclear reaction?
Fusion converts nuclear energy into heat
Fusion demands conditions of extremely high temperature to produce it
Fusion produces large amount of heat
Fusion reactions takes place in the sun
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
In the fuse of an electrical installation blows out
replace the fuse by a thin wire
replace the fuse by a thick copper wire
replace the fuse by a fuse wire of proper rating
replace the fuse by nichrome wire
When a steel ball is placed on the surface of mercury, it does not sink because
of the surface tension of mercury
mercury is a semi-solid
of the high viscosity of mercury
the density of mercury is greater than that of steel
The aneroid barometer uses
mercury
distilled water
alcohol
does not use any liquid
The escape velocity of a satellite projected from the surface of the earth is independent of
the mass of earth
the mass of the satellite
the radius of the earth
gravitation of the earth
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
Thick brick walls are used in the construction or a cold storage because bricks
are good conductors of heat
are cheaper
are easily obtained
are bad conductors of heat
Water kept in an earthen pot is less cool on rainy days than in summer because during the rainy days
the pores in the pot are closed
rain water stops oozing out from the pores
the water that oozes out does not evaporate quickly because of the large percentage of moisture in the air
surface of the pot becomes damp
Powder clings to the skin because of
cohesion
adhesion
capillary action
absorption
The minimum velocity required by a satellite to escape earth's gravitational pull is
18 km/s
11.2 km /s
21 km/s
35 km/s
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 speed of light is minimum while passing through
air
glass
vacuum
water
In a microphone
sound energy is converted into electrical energy
electrical energy is converted into sound energy
sound energy is converted into mechanical energy
mechanical energy is converted into sound energy
The electrical domestic tube light gives white fiourescent light because of
collision between molecules of filled gas under electric current
heavy current
vacuum inside the tube
falling of ultra violet rays on the white inner coating of the tube
The largest planet in the solar system is
Neptune
Uranus
Jupiter
Saturn
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
The unit of power in SI is
Joule
Newton
Joule/Sec
Erg/Sec
X-rays are
deflected by electric field
deflected by magnetic field
slightly deflected by electric field and magnetic field
not deflected by electric and magnetic fields
The red colour of the setting sun is due to
the least scattered red colour reaching the eye
the dispersion of sun light occurred in air molecule in atmosphere
the diffraction of sunrays in atmospheric layers
interference of all the rays coming from the sun