The stars that shine brightly then dimly and then brightly are known as
meteors
binaries
variable stars
bright stars
Correct Answer :
C. variable stars
Related Questions
In a refrigerator, the refrigerant is
Nitrogen
Oxygen
Chlorine
Freon
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
Separating particles from a suspension is effected by
centrifugal force
frictional force
gravitational force
distillation
Sound waves In 'air travel faster if
frequency is higher
wavelength is smaller
pitch is smaller
air is warmer
Expansion of a rod when heated
is proportional to its original length
is proportional to the increase of temperature
is inversely proportional to its original length
Both (a) and (b) above
A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will
increase
decrease
remain unaffected
have its shape changed
If an empty cylinder Is half ruled with a liquid, Its centre of gravity is
shifted upwards
shifted downwards
shifted neither upward nor downward
shifted upward or downward depending on the density of the liquid
The light from the star nearest to the sun reaches the earth in
8 minutes
4.3 years
12 seconds
24 hours
During thunder storm you are travelling in a car. To protect yourself from the lightning you will have to
remain in the car
get out of the car and lie flat in the ground
abandon the car and take shelter under a nearby tree
touch the nearest electric pole
Compared to the atomic bomb, the destructive power of a hydrogen bomb is
greater
less
equal
can't be determined
If a bar magnet is broken into two pieces
both pieces will lose their magnetism
one piece will have North Pole on both ends and the other South Pole on its both ends
each will remain a magnet with North Pole at one end and South Pole at the other
the longer piece will behave as a bar magnet while the smaller will have no magnetism at all
On the Kelvin scale, the melting point of ice is
0 K
273 K
373 K
100 K
An electric kettle used for boiling hard water has a white scale deposited on its heating element. This consists or
sugar
sodium carbonate
common salt
carbonates of calcium and magnesium
The maximum displacement of the particle in a mechanical wave motion is known as
amplitude
vibration
frequency
phase
Isotones are species of atoms containing
same number of protons but different number of neutrons
same number of neutrons but different number of protons
the same total number of protons and neutrons
same number of protons and different number of electrons
The source of electric energy in an artificial satellite is
mininuclear reactor
a dynamo
a thermopile
solar cells
Of the following which has got the highest frequency?
ultraviolet rays
gamma rays
radio waves
infrared waves
The neutron, one of the constituent particles of which the nuclei of atoms are composed was discovered by
Irene Curie
W Bothe and H Becker
James Chadwick
Jean Joliot
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
The colour or an opaque object is due to the colour it
absorbs
refracts
reflects
scatters
A solar eclipse occurs when the earth, the sun and the moon are in a straight line, and
when the moon passes between the sun and the earth
when the sun comes between the earth and the moon
when the earth comes between the sun and the moon
on a full moon day
The Indian Satellite System used for domestic communications, television and meteorology is known as
INSAT
Bhaskara
Aryabhatta
All the above
Every action has an equal and opposite reaction is Newton's law of Motion
first
second
third
fourth
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
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
The asteroids belt lies between the orbits of
Earth and Mars
Venus and Earth
Mars and Jupiter
Moon and Mars
The barometer was invented by
Michael Faraday
Torricelli
Thomas Alva Edison
Benjamin Franklin
Sound waves
are electromagnetic waves
can easily pass through vacuum
are always transverse waves
require a material medium for propagation
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
We see the sun before it actually rises on the horizon. This is due to
refraction
reflection
total internal reflection
parallax