Which of the following wires of same dimensions offers least resistance to the ,flow of current?
copper
aluminium
silver
nichrome
Correct Answer :
C. silver
Related Questions
Radio waves sent out by radio stations are reflected by
troposphere
stratosphere
mesosphere
ionosphere
The focal length or lens or the eye is under the control or the
iris
pupil
ciliary body
cornea
The end product in the uranium disintegration series is
lead
zinc
carbon
tin
Which of the following revolves round the nucleus in an atom?
protons
electrons
neutrons
positrons
A stone floor feels cold to the bare feet but a carpet on the same floor feels warm. This is because
the floor and carpet are at different temperatures
the stone conveys the heat away from the feet more rapidly than the carpet
the carpet is a better conductor of heat than the stone
the human body maintains a constant temperature
Increase in pressure
has no effect on the boiling point of a liquid
raises the boiling point of a liquid
lowers the boiling point of a liquid
increases the volume of a liquid
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
When two similar sources vibrate with slightly different frequencies, a regular rise and fall occurs in the loudness of tone. This phenomenon Is known as
doppler effect
beats
resonance
echo
Echoes are produced by
the reflection of sound waves
the refraction of sound waves
the interference of sound waves
reverberation of sound waves
The characteristics of a musical note are
loudness
pitch
quality or timbre
All the above
Light from the sun reaches the earth in
2 minutes
4 minutes
12 minutes
8 minutes
Which of the following is wrongly matched?
electric current - ampere
resistance - Ohm
electric power - volt
electric charge Coulomb
Sound waves
are electromagnetic waves
can easily pass through vacuum
are always transverse waves
require a material medium for propagation
The device that is used to measure the electromotive force of a cell is
an ammeter
a rheostat
a voltmeter
a voltameter
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
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
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
The coil of an electric heater is made of
Platinum
Tungsten
Nichrome
Copper
In a dynamo
mechanical energy is converted to light energy
mechanical energy is converted to heat energy
mechanical energy is converted to electrical energy
electrical energy is converted to mechanical energy
Sound waves In 'air travel faster if
frequency is higher
wavelength is smaller
pitch is smaller
air is warmer
To produce beats it is necessary to have two waves
travelling in opposite direction
of slightly different frequencies
of equal wavelength
of equal amplitude
The device used to record the sound is
a microphone
a headphone
a phonograph
an amplifier
Less dew is formed on cloudy nights because
there is no moisture in the atmosphere
clouds absorb the falling dew
objects emit radiant energy very fast on such nights
objects lose less radiant energy
A person does not sink in the Dead Sea because
the sea contains a large amount of other salts besides sodium chloride
the density of the person is less than the density of the Dead Sea water
of the surface tension due to salt water in the Dead Sea
of difference in mass
The world's first artificial satellite Sputnik I was launched by Russia in
1985
1957
1959
1960
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
The brightest planet in the Solar System is
Jupiter
Mercury
Venus
Sirius
In experiments on static electricity the standard method for obtaining small amounts of positive electricity is to rub
a glass rod with flannel
an abonite rod with flannel
a glass rod with silk
Any of the above
An ohm is a unit of
potential difference
resistance
current
All the above
The orbit of Venus lies between those of
Mercury and Earth
Earth and Mars
Mars and Saturn
Mars and Jupiter