Choose the correct answer
Microphone converts sound energy into electrical energy.
Electric fan converts electrical energy into mechanical energy.
Battery converts chemical energy into electrical energy.
All the above
Correct Answer :
D. All the above
Related Questions
The property of a fluid by which it resists relative motion within itself is known as
cohesive force
surface tension
diffusion
viscosity
Thick brick walls are used in the construction or a cold storage because bricks
are good conductors of heat
are cheaper
are easily obtained
are bad conductors of heat
A person cups his hand around the mouth when shouting. Why?
Sound energy from his mouth is then directed in one direction
The cupped hand acts as a cardboard tube of short length
The pitch of sound increases
Both (a) and (b)
At what temperature do the Fahrenheit and Celsius scales give the same reading?
212°
32°
-40°
0°
A cyclist leans inwards when he is negotiating a curve 10 that
he may increase his speed
his weight may be reduced
necessary centripetal force may be available from the horizontal component of the normal reaction due to the track to maintain the curved motion
no frictional force may be produced between the wheels and the axle
The hygrometer is an apparatus used for finding the
temperature of air
intensity of light
density of a liquid
relative humidity of the atmosphere
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
Of the following which has got the highest frequency?
ultraviolet rays
gamma rays
radio waves
infrared waves
When a body is projected upwards
the time for the upward journey and downward journey are the same
the upward journey takes more time
the downward journey takes more time
Can't be said
Fish and other aquatic creatures can live inside a deep frozen pond because
fish are cold-blooded animals
ice is a bad conductor of heat
there will always be water just beneath the ice level
they can adapt themselves to live in ice
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
Electromagnets are used in
the telephone ear piece
the telegraph
the electric bell
All the above
Where does the centre of gravity of a rubber ring lie?
on the outer surface
in the inner surface
at the centre of the ring
None of 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 transistor was invented by
Marconi
Baird
John Bardeen, Walter H. Brattain and William Shockley
Edison
Stars twinkle because of
refraction of light from them through air
reflection
absorption
All the above
The strength of an electromagnet can be increased by
increasing the length of the coiled wire
increasing current supply
increasing the size of the iron core
All the above
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
The velocity required to place a vehicle in orbit round the moon is _________ that required to place it in orbit round the earth.
less than
greater than
equal to
greater than or equal to
The Space Application Centre for training in Satellite Communication Technology is located at
Bangalore
Mumbai
Ahmedabad
New Delhi
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
Where does the centre of gravity of a rubber ring lie?
on the outer surface
in the inner surface
at the centre of the ring
None of the above
Which is the densest planet of the solar system?
Sun
Jupiter
Mercury
Earth
The acoustical quality of a room depends on
the size and shape of the room
the ability of the ceiling, walls and floor to exclude unwanted sound
the use of furnishings made of sound absorbing materials
All the above
A rheostat is used
to increase the current flow in a circuit
to decrease the current flow
to measure the flow of electric current
Either (a) or (b) above
Sun spots are
the mountains found on the surface of the Sun
the dark patches on the sun having less temperature than the normal sun's surface
ionized gas found near the solar surface
the magnetic storms on the surface of the Sun
Astigmatism, a structural defect of the eye, is due to
the eye lens being thin
the eye lens being thick
lack of symmetry in the curvature of the eye preventing rays of light from being brought to a common focus
the pupil being very small
The shadow below a tree has bright spots in it because
light comes through circular gaps between the leaves
the leaves are circular
the rays bend to form circular spots
the gaps between the leaves act as pin holes
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
When the resistance of a circuit increases the current will
increase
decrease
remain the same
None of the above