Electromagnets are used in
the telephone ear piece
the telegraph
the electric bell
All the above
Correct Answer :
D. All the above
Related Questions
A nuclear reactor is said to have become 'critical' when
it stops due to malfunctioning
it starts emitting dangerous radioactive radiations
it is shut down to avoid explosion
it is ready to produce controlled energy
X-rays are used
in hospital in the treatment of malignant growth
to reveal hidden flaws in metal castings and welded joints
to detect alterations made in works of art
All the above
The device that is used to measure the electromotive force of a cell is
an ammeter
a rheostat
a voltmeter
a voltameter
The filament used in the electric lamp is made of
nichrome
tungsten
copper
aluminium
No current will flow between two charged bodies if they have the same
resistance
charge
potential
charge/potential ratio
Halley's comet appears in the heavens once in
40 years
50 years
76 years
80 years
The Solar System lies near the edge of a galaxy known as
The Milky Way
Radio Galaxy
Andromeda Nebula
Magellanic Clouds
Choose the scalar quantity from the following physical quantities
force
velocity
acceleration
speed
Changing of one element into another element is known as
transmutation
fission
fusion
radioactivity
The temperature of a large bucket-full of hot water (a few degrees below boiling point) is lower than a beaker full of boiling water. But
the hot water contains a much larger quantity of internal energy than the boiling water
the boiling water contains more quantity of internal energy than the warm water
both of them have got the same amount of internal energy.
nothing can be said definitely with the data given
Every action has an equal and opposite reaction is Newton's law of Motion
first
second
third
fourth
The overhead wires supported by high towers in the grid system carry
alternating current of very high frequency
alternating current of very high voltage
a very large direct current
a high voltage direct current
Railway tracks are banked on curves so that
the necessary centrifugal force may be obtained from the horizontal component of the weight of the train
the frictional force between the track and the wheels is avoided
the necessary centripetal force may be derived from the horizontal component of the weight of the train
None of these
Which part of the eye photographic camera?
Lens
Iris
Retina
Eyelid
The first Indian Satellite launched from a Russian Cosmodrome on April 16, 1975 was named
Bhaskara
Insat I-A
Aryabhatta
SLV-l
The distance between two bodies is halved. Now the force of attraction between them will be
half
one fourth
four times
two times
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
The heat generated in a conductor carrying current is proportional to
the resistance
the square of the current flowing through it
the time the current flows
All the above
The device used to record the sound is
a microphone
a headphone
a phonograph
an amplifier
When a body Is taken to the poles from the equator, Its weight becomes
greater
less
the same
None of these
If you want to open a door with les difficulty you push it
at the middle
at a point away from the hinge (near the rim)
near the hinge
None of the above
Which of the following has the highest refractive index?
Crown glass
Water
Flint glass
Diamond
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
Of the following types of electromagnetic radiation which has the longest wavelength?
ultraviolet rays
gamma rays
radio waves
infrared waves
Nichrome is used in electric heaters and irons because
it resists oxidation when red hot
its melting point is high
it has got 60 times the resistance of copper
All the above
Chronometer la an instrument to measure
heat
electric potential
time
distance between two points
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
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
Which of the following can produce electricity?
resistor
thermocouple
light bulb
neon tube
An electric charge is measured in
coulomb
ampere
volt
watt