A heavenly body similar in nature to the sun intensely hot glowing mass that produces its energy by thermonuclear reactions is
a planet
a meteor
a star
a comet
Correct Answer :
C. a star
Related Questions
A proton is
a quantum of light energy
a quantum of matter
a positively charged atomic particle
another name for positron
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 speed of sound in air at 0° C is approximately
4 x 10 8 m/s
1500 m/s
330 m/s
500 m/s
Sound waves in air are
transverse
longitudinal
transverse and longitudinal
neither transverse nor longitudinal
If you want a sound proof room, the walls should be
able to refract the sound
good absorbers of sound
good reflectors of sound
All the above
Like magnetic poles
attract each other
repel each other
neither attract nor repel
attract or repel depending upon the conditions
The device that is used to measure the electromotive force of a cell is
an ammeter
a rheostat
a voltmeter
a voltameter
A balloon ruled with hydrogen will
continue going upwards uninterrupted
reach a particular height and remain floating
burst after reaching some height
reach a particular height and start coming down
Galaxies emit
radio waves and X-rays
ultraviolet light waves
visible light waves
All the above
When a body Is taken to the poles from the equator, Its weight becomes
greater
less
the same
None of these
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
The theory that the earth constituted the centre of the universe around which the sun and the planets revolved was propounded by
Copernicus
Ptolemy
Newton
Kepler
The number of galaxies that are visible without telescope on clear dark nights and away from bright lights is
one
two
three
infinite
When temperature decreases, resistance of metals to flow of electricity
increases
decreases
neither increases nor decreases
first increases then decreases
Frictional force acts in
the same direction as the motion
the opposite direction of the motion
all the directions
upward direction
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°
When a body Is taken to the poles from the equator, Its weight becomes
greater
less
the same
None of these
The brightest planet in the Solar System is
Jupiter
Mercury
Venus
Sirius
We always see only one side of the moon because
the sun comes in between the earth and moon
the moon is stationary
the time taken by the moon to rotate on its axis is the same as the time taken by it to revolve round the earth
moon revolves round the sun
When a satellite la In a geostationary orbit the force keeping it in orbit Is
zero
the centrifugal force
reaction due to steady burning of fuel
the gravitational pull on the body by the earth is the weight of the body which provides the centripetal force
The colour or an opaque object is due to the colour it
absorbs
refracts
reflects
scatters
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 source of electric energy in an artificial satellite is
mininuclear reactor
a dynamo
a thermopile
solar cells
The mixing up of two gases as a result of random motion of molecules is called
diffusion
effusion
vaporisation
sublimation
A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift is
greater than the weight of the man
less than the weight of the man
same as the weight of the man
zero
In the case of bodies falling under gravity which of the following remains constant at a given place?
kinetic energy
potential energy
acceleration
All the above
Powder clings to the skin because of
cohesion
adhesion
capillary action
absorption
A boy sitting in a train moving with a uniform velocity drops a coin outside. A man standing outside the train will find the trajectory of the coin to be
a parabola
a horizontal straight line
a vertical straight line
a circle
Photocells are used
in burglar alarms
in automotive devices for light switches
television cameras
All the above
Dioptre is the unit of power of
convex mirrors
concave mirrors
concave lenses
lenses irrespective of types