Which of the following revolves round the nucleus in an atom?
protons
electrons
neutrons
positrons
Correct Answer :
B. electrons
Related Questions
The instrument used to measure the strength of electric current at a point is
Ammeter
Altimeter
Adrinometer
Anemometer
One can be recognised by his voice alone due to the factor of
quality
amplitude
pitch
loudness
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
A series of east moving still pictures can be made to appear as a moving picture because the eye
can focus very rapidly as pictures change
is quicker than the brain
can see two images separated only if the interval' between seeing them is more than' one-tenth of a second
can shut out some of the light
Tea pots are highly polished
so that they may reflect thermal radiation from outside and minimise such radiation from them
so that they may absorb all radiation from outside
to make them attractive to look at
because they take high polish
A convex mirror always produces
an erect, virtual image of diminished size
an erect, real image of diminished size
an erect, real image of double size
a virtual image of double size
The device used to record the sound is
a microphone
a headphone
a phonograph
an amplifier
A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift is
greater than the weight of the man
less than the weight of the man
same as the weight of the man
zero
Under similar conditions of temperature and pressure, the velocity of sound is maximum in
helium
argon
hydrogen
oxygen
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
A pressure gauge for fluids is called
a hydrometer
a manometer
a lactometer
an anemometer
A light year means
a unit of time
a unit of length
a year of no consequence
illumination throughout the year
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
A radio set that uses valves does not start operating immediately when it is switched on whereas a set containing only tranaistors operates immediately. The reason for this is that
the valve filaments have low resistance
valve-radio sets work at a higher voltage
transistor set has a low resistance
filaments of the valves cake time to beat up and function
Radio waves sent out by radio stations are reflected by
troposphere
stratosphere
mesosphere
ionosphere
On the Kelvin scale, the melting point of ice is
0 K
273 K
373 K
100 K
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
A man weighing 50 kg floats on water in a lake. His apparent weight is
50 kg
45 kg
zero
150 kg
Light from the sun reaches the earth in
2 minutes
4 minutes
12 minutes
8 minutes
Moon has no atmosphere because
it has no population
it is quite far off
its surface is full of rocks
its gravity is not sufficient for any atmosphere to hold on to it
The temperature, surface features, length of days and nights of a planet depend on
its atmosphere
its distance from the sun
its rotation
All the above
The spectrum of white light can be studied by
a microscope
a telescope
a stereoscope
a spectroscope
When a bullet is fired from a gun
the gun moves forward
the gun jumps up
the gun does not move
the gun recoils with the same momentum as the bullet
A pressure gauge for fluids is called
a hydrometer
a manometer
a lactometer
an anemometer
A thermostat is a device used
for automatically maintaining a steady temperature
for measuring electricity
to reduce the voltage of electricity
for producing heat
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
Tap water is placed in an open pad and allowed to evaporate. After some time the temperature of water
increases to a great extent
increases slightly
decreases slightly
decreases rapidly
The pressure of air at high altitude is less than the atmospheric pressure at the sea level. Hence the boning point of water at a hill top
is more than at sea level
is equal to that sea level
is less than at sea level
depends on the surrounding temperature
When an incident beam of light strikes the surface of a glass slab normally, the refracted beam
goes straight through without bending
gets deviated away from the normal
gets bent towards the normal
gets reflected
The image of an object formed in a plane mirror
is real
is virtual
can be obtained on a screen
is slightly bigger than the object