Of the following types of electromagnetic radiation which has the longest wavelength?
ultraviolet rays
gamma rays
radio waves
infrared waves
Correct Answer :
C. radio waves
Related Questions
At what temperature do the Fahrenheit and Kelvin scales give the same reading?
212°
32°
-40°
0°
Photo-electric cells convert
electrical energy into light energy
light energy into electrical energy
light energy into heat energy
electrical energy into heat energy
Increase in pressure
increases the melting point of ice
decreases the melting point of ice
has no effect on the melting point of ice
increases the volume of the ice
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
A piece of cork la embedded inside an ice block which floats in water. What will happen to the level of water when all ice melts?
It will go down
It will come up
It will remain at the same level
First it will go down and it will come up
Out of the following, name the fluorescent substance.
quinine sulphate solution
paraffin oil
fluorescein solutions
All the above
A star contains
about 75% of hydrogen
22% helium
traces of most other elements including oxygen, neon, carbon and nitrogen
All the above
If an object is placed between two parallel plane mirrors, the number of images formed will be
1
infinite
0
4
It is easier to climb down a staircase than climb up because in climbing down
work is done against gravity
the steepness of the staircase isn't felt
gravity assists
there is no friction between the legs and steps
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
The stars that shine brightly then dimly and then brightly are known as
meteors
binaries
variable stars
bright stars
If an empty cylinder Is half ruled with a liquid, Its centre of gravity is
shifted upwards
shifted downwards
shifted neither upward nor downward
shifted upward or downward depending on the density of the liquid
A piece of cork is embedded inside an ice block which floats in water. What will happen to the level of water when all ice melts?
It will go down
It will come up
It will remain at the same level
First it will go down and it will come up
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
The force that keeps a body in a circular motion la called
the centripetal force
the centrifugal force
the frictional force
All the above
When ice just melts
there is no change in volume
there is no change in temperature
heat is given out
there is no change of state
When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is
the violet ray
the red ray
the green ray
the blue ray
In an oil lamp, holes are provided below the chimney so that
necessary oxygen for burning of oil may be provided
the convection current of air may be maintained to keep the lamp burning
the brightness of the lamp may be increased
All the above
If a body is taken from the earth to the moon
both its mass and weight will be different
its mass will be different but the weight will remain the same
its mass and weight will both remain unchanged
its mass will remain the same but weight will be different
Water kept in an earthen pot is less cool on rainy days than in summer because during the rainy days
the pores in the pot are closed
rain water stops oozing out from the pores
the water that oozes out does not evaporate quickly because of the large percentage of moisture in the air
surface of the pot becomes damp
A device used in a ship for the purpose of measuring the depth of the sea is
an altimeter
a fathometer
a hydrometer
a sonometer
In compact porous soil, the rising of the water is due to
capillarity
cohesion
adhesion
viscosity
Air escaping rapidly from a narrow orifice in an inflated tyre feels cool because
the speed with which it escapes cools it down
of the higher temperature of the surroundings
of sudden expansion causing loss of internal energy
there is no real fall in temperature
Which of the following is known as freon?
Liquid ammonia
Carbon tetrafluoride
Dichloro-difluoro-methane
Sulphur dioxide
A proton is
a quantum of light energy
a quantum of matter
a positively charged atomic particle
another name for positron
A proton is
the ionised hydrogen molecule
the nucleus of helium atom
the nucleus of hydrogen atom
the positive counterpart of electron
Sound waves in air are
transverse
longitudinal
transverse and longitudinal
neither transverse nor longitudinal
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
Solar radiation is preferred to other sources of energy because
it is practically inexhaustible
it is the cheapest form of energy
it does not cause pollution
All of the above
The mode of travel of heat energy from the sun across the empty space beyond the earth's atmosphere is known as
conduction
convection
radiation
absorption