Which of the following is not electromagnetic waves?
heat waves
sound waves
radio waves
light waves
Correct Answer :
B. sound waves
Related Questions
Among the following the most suitable material for the core of an electro-magnet is
steel
wood
soft iron
copper
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
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
At what temperature do the Fahrenheit and Celsius scales give the same reading?
212°
32°
-40°
0°
The theory that the earth constituted the centre of the universe around which the sun and the planets revolved was propounded by
Copernicus
Ptolemy
Newton
Kepler
SONAR (Sound Navigation Ranging) is
used by warships and military aircraft to locate enemy submarines
used by ships to determine the depth of water beneath them
a detective device that uses sound to locate under - water objects
All the above
The mirage is a phenomenon
generally considered as a desert happening
caused by unequal heating of the several layers of the atmosphere above the desert
in which the refracted rays take a curved path resulting in total internal refection
All the above
The ozone layer absorbs
Cosmic rays
Infrared rays
All radiations of light
Ultra violet rays coming from the sun
When a steel ball is placed on the surface of mercury, it does not sink because
of the surface tension of mercury
mercury is a semi-solid
of the high viscosity of mercury
the density of mercury is greater than that of steel
The rate of cooling of a hot body depends on
the nature of the radiating surface
area of the radiating surface
temperature difference between the body and the surroundings
All the above
Enriched uranium means
Uranium that is very pure
Uranium in which the concentration of the isotope U-238 is more than in the naturally occuring uranium
Uranium in which the concentration of the isotope U-235 is more than in the naturally occuring uranium
None of the above
When the disturbed electrons of an exited atom transfer back into lower energy levels they emit energy in the form of electromagnetic wave pulses called
neutrons
electrons
phonons
photons
Before the invention of geostationary satellites, television stations could not transmit their programmes to far off places because
these signals are electromagnetic in nature
these are not electromagnetic in nature
their wavelength is very large
they are not reflected by the ionosphere but pass through it
A ship sailing from a river to the sea
sinks less in the sea
sinks more in the sea
neither sinks more nor less in the sea
sinking more or less depends on sea
Which is the densest planet of the solar system?
Sun
Jupiter
Mercury
Earth
At temperature near OK, (zero kelvin) metals such as lead and tin become
insulators
semiconductors
superconductors
condenser
In hot climatic conditions, the buildings are painted white because
white paint is economical
it does not fade off
it does not crack with higher temperature
white coating is a bad conductor of heat and reflects heat rays that fall on it, thus keeping the inside cool
How is it that Pluto is not always the farthest planet of the solar system?
Each planet becomes the farthest planet in its turn. Now it is the turn of Piuto
The Sun is now in the zodiac in which it is nearest to outer planets
The eccentricity of Piuto's orbit being substantial, this orbit cuts the orbit of Neptune
Piuto belongs to other solar system
When the velocity of a body is halved
its momentum is halved
its kinetic energy is halved
its acceleration is halved
its potential energy is halved
The heat produced in a conductor due to the passage of a current through it is proportional to
the square of the current
the resistance of the conductor
the time for which the current flows
All the above
To concentrate light on the defective teeth, the dentists use
convex mirrors
concave mirrors
convex lens
concave lens
Which mirror is used as a rear view mirror in Vehicles?
Parabolic
Convex
Concave
Plain
The unit of heat energy is
watt
degree
joule
erg
The force of attraction or repulsion between two charged bodies is directly proportional to the product of the charges and inversely proportional to the square of distance between them. This was propounded by
Coulomb
Gilbert
Volta
Rutherford
The earth's nearest neighbour in space is
the Sun
the Moon
the Venus
the Mars
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
The difference between planets and stars is
planets do not have light of their own whereas stars shine by their own light
planets do not twinkle like stars
planets are much smaller than stars
All the above
Which of the following is not electromagnetic waves?
heat waves
sound waves
radio waves
light waves
The colour of a star is an indication of its
distance from the earth
age
temperature
size
Which of the following has the highest refractive index?
Crown glass
Water
Flint glass
Diamond