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
Correct Answer :
D. white coating is a bad conductor of heat and reflects heat rays that fall on it, thus keeping the inside cool
Related Questions
Bats flying in the dark avoid obstacles because
they can see very dearly only in darkness
they produce ultrasonic waves which guide them
their eyes are sensitive to darkness
their eye holes expand in darkness
Air pressure is usually highest when the air is
warm and moist
cool and dry
warm and dry
cool and moist
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
Changing of one element into another element is known as
transmutation
fission
fusion
radioactivity
Galaxies emit
radio waves and X-rays
ultraviolet light waves
visible light waves
All the above
The principle of equivalence of mass and energy was established by
Dalton
Rutherford
Einstein
Planck
Of the following which has got the highest frequency?
ultraviolet rays
gamma rays
radio waves
infrared waves
The characteristics of a musical note are
loudness
pitch
quality or timbre
All the above
The stars that shine brightly then dimly and then brightly are known as
meteors
binaries
variable stars
bright stars
Which of the following is fissionable?
U-234
U-235
U-238
Both (b) and (c)
In a refrigerator cooling is produced by
the ice that deposits on the freezer
the evaporation of a volatile liquid
None of the above
Both (a) and (b)
The light from the star nearest to the sun reaches the earth in
8 minutes
4.3 years
12 seconds
24 hours
The focal length or lens or the eye is under the control or the
iris
pupil
ciliary body
cornea
When temperature decreases, resistance of metals to flow of electricity
increases
decreases
neither increases nor decreases
first increases then decreases
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
The speed of sound in a medium depends upon the properties of the medium such as
its density
its temperature
its elasticity
All the above
The cover of a solar cooker is made of glass because
it absorbs sun's rays
it reflects sun's rays
it retains the heat inside by the greenhouse effect
it radiates heat better than metals
A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance
will increase
will decrease
does not change
varies with the increase of depth of the immersion of the iron piece
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
The earth satellite Aryabhatta was put in orbit by India on
October 20, 1978
November 14, 1978
January 26, 1979
April 19, 1975
Out of the following, name the fluorescent substance.
quinine sulphate solution
paraffin oil
fluorescein solutions
All the above
A lightning conductor installed in a building
does not allow the lightning to fall on the building at all
drives away the charged clouds
forces the lightning to fall on other buildings near that building
conducts the electric charges to the ground when lightning strikes the building
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
For an electron orbiting in a hydrogen atom, the necessary centripetal force keeping it in orbit is provided by
the electrical attraction between the negatively charged electron and the positively charged porton
the high speed of the electron
the low speed of the electron
gravity
Water has maximum density at
0° C
-15° C
4° C
15° C
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
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
The function of a ruse wire is
to stabilise the voltage
to decrease the current supply
to increase the current supply
to prevent an unduly high current from passing through a circuit
Which metal is used in storage batteries?
Copper
Lead
Tin
Iron
When a body is immersed in a fluid the force of buoyancy of the fluid on the body depends on
the immersed volume of the body
density of the liquid
acceleration due to the gravity at the place
All the above