Who first established the fact that the earth revolves round the sun?
Sir Isaac Newton
Kepler
Copernicus
Ptolemy
Correct Answer :
C. Copernicus
Related Questions
The world's first artificial satellite Sputnik I was launched by Russia in
1985
1957
1959
1960
Out of the following, name the fluorescent substance.
quinine sulphate solution
paraffin oil
fluorescein solutions
All the above
The SI unit of electric current is
the ampere
the volt
the ohm
the coulomb
Some persons are not able to see distant objects clearly because the image of the object is focused in front of the retina. This defect is known as
short sight
long sight
astigmatism
presbyopia
Among the following the most suitable material for the core of an electro-magnet is
steel
wood
soft iron
copper
Frictional force acts in
the same direction as the motion
the opposite direction of the motion
all the directions
upward direction
A star contains
about 75% of hydrogen
22% helium
traces of most other elements including oxygen, neon, carbon and nitrogen
All the above
A pair of stars that revolve round each other is
a neutron star
a binary star
a dwarf star
a polar star
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
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
The instrument used to measure atmospheric pressure is
Pyrometer
Eudiometer
Barometer
Hydrometer
Some persons are not able to see distant objects clearly because the image of the object is focused in front of the retina. This defect is known as
short sight
long sight
astigmatism
presbyopia
When we sweat, we feel comfortable under a fan because
the air circulated by the fan is cool
the fan produces convection currents of air
the air circulated by the fan quickens the evaporation of the moisture on our skin
the air takes away the heat from our body
The attraction of unlike molecules at the common surface is known as
adhesion
cohesion
surface tension
capillarity
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
The power of a lens is
equal to its focal length
equal to its radius of curvature
equal to the reciprocal of its focal length (in metres)
equal to twice its focal length
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 atmosphere gets heated up mainly by
direct sun's rays
radiation from earth's surface
radiogenic heat (resulting from radioactive decay)
cosmic rays coming from space
The earth satellite Aryabhatta was put in orbit by India on
October 20, 1978
November 14, 1978
January 26, 1979
April 19, 1975
Which of the following sets of elementary particles have nearly equal masses?
Neutron and Proton
Electron and Proton
Neutron and Electron
Proton, Neutron and Electron
The body of an electrical appliance is earthed in order that
electricity may not leak
there may be smooth flow of electricity
a short circuit may be prevented
current may pass to the earth in case of a short circuit without doing any harm to the person
Electromagnets are used in
the telephone ear piece
the telegraph
the electric bell
All the above
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
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 spectrum of white light can be studied by
a microscope
a telescope
a stereoscope
a spectroscope
When a whistling engine approaches a person standing on the platform, the frequency or the note
appears to increase
appears to decrease
does not change at all
first increases then decreases
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
Two tumblers stuck together can be separated by
pouring ice cold water into the inner tumbler
pouring ice cold water on the outer tumbler
pouring hot water into the inner tumbler
dipping both the tumblers in hot water
A pair of stars that revolve round each other is
a neutron star
a binary star
a dwarf star
a polar star
Every action has an equal and opposite reaction is Newton's law of Motion
first
second
third
fourth