Light from the sun reaches the earth in
2 minutes
4 minutes
12 minutes
8 minutes
Correct Answer :
D. 8 minutes
Related Questions
Red Light is used as a dancer signal because
it is pleasing to the eye
it has a traditional colour
it is easily distinguishable
it is most sensitive to the human eye
The colour of the light which travels through glass with minimum speed is
red
violet
green
yellow
In experiments on static electricity the standard method for obtaining small amounts of positive electricity is to rub
a glass rod with flannel
an abonite rod with flannel
a glass rod with silk
Any of the above
A rod of brass is held in hand and rubbed with fur. The rod is found to have
no charge
positive charge
negative charge
can't be said
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
At temperature near OK, (zero kelvin) metals such as lead and tin become
insulators
semiconductors
superconductors
condenser
When one enters a dark room after being in bright light one is not able to see anything clearly for a while because
the retina of the eye moves forward
the retina of the eye moves backward
c).the iris is unable to dilate the pupil immediately to be able to see things
the eye has no power of accommodation
Which of the following sets of elementary particles have nearly equal masses?
Neutron and Proton
Electron and Proton
Neutron and Electron
Proton, Neutron and Electron
Why is it cool near an open pond on a hot summer day?
Evaporation at the surface causes cooling
The heat obsorbed at the surface is passed on to the bottom
Because of impurity in the water
Because of convection currents set up inside water
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
Hot water is poured simultaneously in four metallic tumblers painted outside with different paints. After some time the water will be found to have cooled most in the tumbler painted.
rough white
rough black
shining white
shining black
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
Mica is used in an electric iron because it is a
good conductor of heat
good conductor of electricity
bad conductor of electricity
Both (a) and (b) above
The sun continuously produces an enormous amount of energy. This is due to
nuclear fission
nuclear fusion
chemical combustion
boiling
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
Lightning is produced when
similar charges of electricity rush towards each other and then get repelled
clouds strike against impurities in air and the friction burns up these impurities
strong opposite charges in different clouds break down the resistance offered by the intervening air
water vapour produces electricity in the clouds
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
Air pressure is usually highest when the air is
warm and moist
cool and dry
warm and dry
cool and moist
Railway tracks are banked on curves so that
the necessary centrifugal force may be obtained from the horizontal component of the weight of the train
the frictional force between the track and the wheels is avoided
the necessary centripetal force may be derived from the horizontal component of the weight of the train
None of these
Pieces of camphor placed on water move about rapidly. This is because of
diffusion
viscosity
surface tension
capillarity
A bullet is fired at a certain angle with the horizontal. Its path will be
elliptical
a straight line
a parabola
a vertical line
Water has maximum density at
0° C
-15° C
4° C
15° C
The atmosphere gets heated up mainly by
direct sun's rays
radiation from earth's surface
radiogenic heat (resulting from radioactive decay)
cosmic rays coming from space
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
Which of the following rays has the highest penetrative power?
�± -rays
�² -rays
�³ -rays
X-rays
It is more difficult to walk on ice than on a concrete road because
there is very little friction between the ice and feet pressing it
ice is soft when compared to concrete
there is more friction between the ice and feet
None of the above
On the Kelvin scale, the melting point of ice is
0 K
273 K
373 K
100 K
Heat is transmitted from one end of a metal rod to its other end by the method of
conduction
convection
radiation
sublimation
The leader of the team who succeeded in constructing the first nuclear reactor (an atomic pile) in the world was
Albert Einstein
Enrico Fermi
HJ Bhabha
Sir Isaac Newton