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
Correct Answer :
B. the greenhouse effect
Related Questions
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
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
A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it lose heat?
conduction and convection only
conduction and radiation only
convection and radiation only
conduction, convection and radiation
The tiniest of the stars belong to the group known as
Giant stars
White Dwarf stars
Neutron stars
Super-giant stars
An electric fan converts
electrical energy into heat energy
electrical energy into mechanical energy
mechanical energy into electrical energy
mechanical energy into heat energy
On the Kelvin scale, the melting point of ice is
0 K
273 K
373 K
100 K
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
When a light ray is reflected repeatedly by a set of parallel plane mirrors, the intensity of light ray diminishes alter a few reflections. This is because of
poor reflection from the mirrors
scattering of light from the mirrors
absorption of some light by the mirrors
absorption of light by the atmosphere
The best estimates of the age of the earth comes from the studies of
angle of inclination of the earth
changes in radio-active minerals in it
period taken by Sun's light to reach the earth
artificial satellites revolving round the earth
Heat is transmitted from one end of a metal rod to its other end by the method of
conduction
convection
radiation
sublimation
The hygrometer is an apparatus used for finding the
temperature of air
intensity of light
density of a liquid
relative humidity of the atmosphere
The speed of sound in air at 0° C is approximately
4 x 10 8 m/s
1500 m/s
330 m/s
500 m/s
The enormous energy released in nuclear and thermonuclear reactions is due to conversion of
chemical energy into heat energy
mechanical energy into heat energy
protons into neutrons
mass into energy according to Einstein's equation
Powder clings to the skin because of
cohesion
adhesion
capillary action
absorption
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
The strength of an electromagnet can be increased by
increasing the length of the coiled wire
increasing current supply
increasing the size of the iron core
All the above
Commonly used safety fuse wire is made of
Tin
Lead
Nickel
An alloy of tin and lead
When ice melts, Its volume
decreases
increases
remains the same until all the ice has melted and then increases
remains the same
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
The stars that shine brightly then dimly and then brightly are known as
meteors
binaries
variable stars
bright stars
Credit for starting Space Science Research in India goes to
HJ Bhabha
SS Bhatnagar
V Sarabhai
CV Raman
In a microphone
sound energy is converted into electrical energy
electrical energy is converted into sound energy
sound energy is converted into mechanical energy
mechanical energy is converted into sound 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 electroplating of a metallic article
protects the article from atmospheric corrosion
gives it a more attractive appearance
Both (a) and (b) above
None of the above
Which mirror is used as a rear view mirror in Vehicles?
Parabolic
Convex
Concave
Plain
Out of the following, name the fluorescent substance.
quinine sulphate solution
paraffin oil
fluorescein solutions
All the above
When light passes from air to glass, its velocity in glass
increases
decreases
remains unchanged
first decreases then increases
The largest reserve of radioactive element which can be used in a nuclear reactor has been found in India, The name of the element is
Thorium
Uranium
Plutonium
Radium
In a longitudinal wave, the direction of propagation of the wave is
the same as the direction of the vibrations of the vibrating body
at right angles to the direction of the vibrations of the vibrating body
Both (a) and (b) above
None of the above
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