Holography is the technique of
taking photos of various objects
recording and reproducing three dimensional images
tracing out planets and stars in the sky
transmitting light waves
Correct Answer :
B. recording and reproducing three dimensional images
Related Questions
When a body is partly or wholly immersed in a liquid the apparent loss of weight is equal to the weight of the liquid displaced by the submerged portion. This is known as
Pascal's law
Bernoulli's law
Archimedes' law
Boyle's law
The ballistic missile, Agni 11, tested by India has a maximum range of
1000 km
1500 km
2000 km
500 km
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
Diamond shines because of its
purity
hardness
high density
high refractive index and low critical angle
Out of the following, name the fluorescent substance.
quinine sulphate solution
paraffin oil
fluorescein solutions
All the above
The asteroids belt lies between the orbits of
Earth and Mars
Venus and Earth
Mars and Jupiter
Moon and Mars
The inside of both the walls of a thermos flask is silvered i.e., on the vacuum side in order to reduce heat loss by
convection
radiation
conduction
All the three
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
A car parked in the sun with its windows closed gets terribly hot inside. This is due to
the heat emitted by the engine
the greenhouse effect
the good conducting power of the metal body
the double layered wind shield
You want a supply of a small but constant current. Which of the following cells will you prefer?
Daniell cell
Leclanche cell
Dry cell
All the above
The asteroids belt lies between the orbits of
Earth and Mars
Venus and Earth
Mars and Jupiter
Moon and Mars
Every action has an equal and opposite reaction is Newton's law of Motion
first
second
third
fourth
A permanent magnet may be demagnetised by
placing it inside a solenoid through which an alternating current is flowing
heating the magnet to redness and then allowing it to cool
dropping it several times or hammering it while lying east-west
All the above
A small bubble of air deep down in a lake rises up to the top of the lake. The volume of the bubble on coming up will
increase
decrease
will not change
first increase and then decrease
The Indian Space Research Organisation (ISRO) is located at
Thumba
Bangalore
Ahmedabad
New Delhi
The heat produced in a conductor due to the passage of a current through it is proportional to
the square of the current
the resistance of the conductor
the time for which the current flows
All the above
Body A is kept in contact with body B. Heat will flow from A to B if
the heat content of A is greater than that of B
the temperature of A is greater than that of B
the specific heat of A is greater than that of B
the specific heat of B is greater than that of A
Rain drops acquire spherical shape due to
viscosity
surface tension
friction
elasticity
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 unit of power in SI is
Joule
Newton
Joule/Sec
Erg/Sec
The line on earth's surface passing through the places having zero dip is called the magnetic equator. This passes through
Thumba
Delhi
Mumbai
Sriharikota
Who first established the fact that the earth revolves round the sun?
Sir Isaac Newton
Kepler
Copernicus
Ptolemy
Halley's comet appears in the heavens once in
40 years
50 years
76 years
80 years
Mercury does not stick to glass because
cohesive forces between the mercury molecules are greater than adhesive forces between mercury and glass molecules
the adhesive forces between mercury and glass molecules are greater than the cohesive forces
both the cohesive and adhesive forces are equal
None of the above
Electromagnets are used in
the telephone ear piece
the telegraph
the electric bell
All the above
Lightning is produced when
similar charges of electricity rush towards each other and then get repelled
clouds strike against impurities in air and the friction burns up these impurities
strong opposite charges in different clouds break down the resistance offered by the intervening air
water vapour produces electricity in the clouds
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°
Pyrometers are instruments used
for measuring the velocity of wind
in the manufacture of fireworks
in finding the coefficient of apparent expansion of a liquid
for measuring high temperatures
Mercury is used in a barometer because
its density being very high 13.6 g/cm3 the height of mercury column is conveniently small
at the ordinary temperature its vapour pressure is small
it is opaque and does not wet glass
All the above
When ice just melts
there is no change in volume
there is no change in temperature
heat is given out
there is no change of state