The frequency of an ultrasonic wave is
the same as that of an audible sound
above the audible range
below the audible range
None of the above
Correct Answer :
B. above the audible range
Related Questions
A pair of stars that revolve round each other is
a neutron star
a binary star
a dwarf star
a polar star
The presence of impurities
lowers the melting point of ice
raises the melting point of ice
has no effect on the melting point of ice
may lower or raise the melting point depending upon the type of impurities
Sound waves in air are
transverse
longitudinal
transverse and longitudinal
neither transverse nor longitudinal
A man weighing 50 kg floats on water in a lake. His apparent weight is
50 kg
45 kg
zero
150 kg
In a refrigerator, the refrigerant is
Nitrogen
Oxygen
Chlorine
Freon
Compared to the atomic bomb, the destructive power of a hydrogen bomb is
greater
less
equal
can't be determined
The power of a lens is
equal to its focal length
equal to its radius of curvature
equal to the reciprocal of its focal length (in metres)
equal to twice its focal length
Cosmic rays contain
protons and electrons
alpha particles
gamma rays
All the above
Why is nuclear fusion also known as thermonuclear reaction?
Fusion converts nuclear energy into heat
Fusion demands conditions of extremely high temperature to produce it
Fusion produces large amount of heat
Fusion reactions takes place in the sun
Nuclear fusion is a process in which
the atoms and molecules lose their identity
nucleus is split into fragments
the nuclear reaction between two light atomic nuclei results in the formation of a heavier nucleus with release of a large quantity of nuclear energy in the process
absorption of neutron by a nucleus
While crossing a suspension bridge, the soldiers are ordered to break steps because
the marching in steps will involve a big strain on them
the resonant vibrations caused by their marching can damage the bridge increasing the amplitude to dangerous proportions
the marching may obstruct other traffic
rumblings of their marching may disturb the surroundings
Metals are good conductors of heat because
they contain free electrons
their atoms are relatively far apart
their atoms collide frequently
they have reflecting surfaces
Which of the following rays has the highest penetrative power?
�± -rays
�² -rays
�³ -rays
X-rays
Drinks kept in a vacuum flask remain hot or cold as the case may be for a long time because
both walls are silvered on the vacuum side
there is vacuum between the double walls
the cork is a poor conductor of heat
of all the above
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
A proton is
a quantum of light energy
a quantum of matter
a positively charged atomic particle
another name for positron
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
Heat is transmitted from one end of a metal rod to its other end by the method of
conduction
convection
radiation
sublimation
Cosmic rays contain
protons and electrons
alpha particles
gamma rays
All the above
Out of the following which is an insulator?
Silver
Copper
Nichrome
Dry wood
Ultrasonic waves are used
in medical and surgical diagnosis
in testing the quality of the linings and pads used in vehicles and aircraft brakes
to clean surgical instruments, jewellery and similar articles
All the above
The Indian Space Research Organisation (ISRO) is located at
Thumba
Bangalore
Ahmedabad
New Delhi
Nuclear fission process means
absorption of a neutron by a nucleus
breakup of the nucleus of a heavy atom into two nearly equal halves emitting two or three neutrons and releasing large amounts of nuclear energy in the process
the scattering of neutrons
formation of heavier nucleus
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
In a freezer ice cubes will be formed more quickly in trays made of
rubber
plastic
aluminium
wood
A heavenly body similar in nature to the sun intensely hot glowing mass that produces its energy by thermonuclear reactions is
a planet
a meteor
a star
a comet
Cosmic rays are
powerful X-rays falling on the earth from space
ultraviolet rays from the sun
gamma rays from radioactive minerals
very energetic radiation falling upon the earth from outer space consisting chiefly of charged particles
A simple mercury barometer is found in a slightly slanting position. The atmospheric pressure
is found by measuring the slanting height of the mercury column
is given by the vertical height
cannot be measured with it
u) can be measured by both the methods described above
When we sweat, we feel comfortable under a fan because
the air circulated by the fan is cool
the fan produces convection currents of air
the air circulated by the fan quickens the evaporation of the moisture on our skin
the air takes away the heat from our body
The colour of a star is an indication of its
distance from the earth
age
temperature
size