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Old Saturday, January 10, 2015
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Smile 100 Important Scientific Questions.

Hello friends these are 100 Important Scientific Questions, which i gone through in two days, please you all must opt this practice try to commit to memory in a day....

1) The Earth bulges out at equator. Why?
Ans: This is due to the shape of the earth. The earth is not a true sphere but it is an ellipsoid. The
equatorial diameter of the earth is 12756.27 kms. While its polar diameter is 12713.505 km. the
difference between its equatorial and polar diameter is about 43 kilometers. The rotation of the
earth on its axis produces a centrifugal force which increases its equatorial diameter. That is
why earth bulges at the equator.

2) The Sun appears red at sunset and sunrise. Why?
Ans: The sun appears red at the time of sunset and sunrise due to the scattering of light by small
particles of dust or smoke near the surface of the earth. The light travels relatively without
hindrance that is why the sun appears red at the time of sunset and sunrise.

3) The ozone layer in the atmosphere is necessary for our survival. Why?
Ans: ozone layer in the atmosphere is very necessary for plant and animal survival because it is
the absorber of ultraviolet rays which are very dangerous for animal health. Ultraviolet rays
cause cancer of skin, spotting of plants etc. that is why the ozone layer is necessary and
essential for animal as well as plant survival.

4) The sky from moon appears black. Why?
Ans: as the moon has no atmosphere, so the sky looks completely black when viewed from
the moon.

5) Roads are bent inwards on curves. Why?
Ans: The roads are bent inwards on the curves and at the turns because the bents avoid
falling outside and prevent the accidents. OR When an object turns in a circle it is influenced
by a centrifugal force which pushes it away from the centre of the circle. When vehicles turn
on a road they fall outside under the influence of centrifugal force. In this way there is
danger of falling or slipping out of road at a turn. Roads are made in a way that these bent
inward at the turns to avoid falling outside and to prevent accidents.

6) Australian continent has winter season when we have summer season in Pakistan.
Ans: the earth on its axis is not at a vertical angle to its orbit. It is inclined at an angle of
about. In this way when the northern hemisphere of the earth is inclined to the sun and
getting direct sun rays, southern hemisphere is inclined away from the sun and getting less
direct rays. Thus the northern hemisphere has summer season and southern hemisphere
has winter season. Pakistan is in the northern hemisphere while Australia is in the southern
hemisphere. So when there is winter in Australia there is summer season in Pakistan.

5) Meat takes longer to cook on mountains.
Ans: The meat takes longer time to cook on the mountains because the atmospheric
pressure decreases with attitude and the boiling point of a liquid is directly proportional to
the atmospheric pressure.

6) Water remains cool in earthen pitcher.
Ans: This occurs due to the process of evaporation. Water gets cooled on evaporation. As
the earthenware pitcher is concerned, they have small pores. Water tends to come out of
pores and evaporates which results in cooling effect on the earthenware and water. While in
the metal pots there are no pores and evaporation does not take place. Besides metal has
tendency to absorb heat that why water does not get cooled in a metal pot.

7) Ice and salt mixture is used as a freezing agent by manual ice-cream makers.
Ans: In manual ice-cream making a mixture of salt and ice is always used because salt has
capacity to reduce the temperature of ice by decreasing its freezing point. That’s why ice
and salt mixture is used as freezing agent in manual ice cream making.

8) It is not advisable to sleep under trees during the night.
Ans: During night the plants release carbon dioxide (CO2) which is a poisonous gas and
injurious to health. That is why it is not advisable to sleep under trees during night.

9) Why the green house operators paint their glass roofs white in summer?
Ans: White colour is the reflector of light and it absorbs less heat as compared to other
colours. As in summer there is already very hot season and heat is not required to that level.
That is why the green-house operators paint glass roofs white in summer season.

12) Water boils quicker on mountains.
Ans: On Mountains the pressure of the air is low due to height, as the air pressure decreases
with altitude. In this way, water boils quicker on mountains at temperature less than 100
degree centigrade, which is the boiling point of water at ground level.

10) Rainbow is produced in the sky after rainfall and sunlight.
Ans: After rain, many droplet of water travel in the atmosphere. When sun rays fall on these
droplets, dispersion of water occurs and droplets act as prism and produce a spectrum of
seven colours. That’s why a rainbow is seen in the sky after rain.

11) Milk is considered as an ideal food.
Ans: Milk is considered as an ideal food due to following reasons: a) It contains all constitute
of balanced diet. b) Milk contains fat. c) Milk has high nutritional value because it contains
proteins as well as minerals.

12) Lunar eclipse last much longer than solar eclipse.
Ans: Lunar eclipse last longer than the solar eclipse because the length of the earth’s umbral
shadow cone is more than three times the average distance between the moon and the
earth, so the shadow is relatively wide at the point where the moon crosses it.

13) Goitre is common in hilly areas.
Ans: Goitre is common in hilly areas because there is deficiency of Iodine in the water.
17) Detergents are better cleaning agents.
Ans: A detergent consists of hydrophilic and hydrophobic ends. In case of dirt the detergent
pushes the dirt off the wet surface of the fabric. The washing machine provides the
agitation.

18) Decomposers are important for life.
Ans: Decomposers break down animal waste and dead organisms in order to get energy and
release free nutrients back into the ecosystem.
OR
Decomposers break down organics into nutrients, which can be used by living organisms to
create new life.

19) Places near sea are cooler in summer.
Ans: Sea water keeps the temperature moderate. In the summer season the places located
near sea are cooler due to the lower temperature of water.

20) Colour blindness is more common in men than women.
Ans: Women have the sex chromosomes XX, while men have the chromosomes XY. The gene
for normal colour vision is found on the X-chromosome. If a woman has one X-chromosome
with the gene and one without it, she will not be colour blind. On the other hand, a man with
an X-chromosome that is missing the gene has no 'backup'. He will definitely be colour
blind. Colour blind women have both X-chromosomes missing the colour vision gene. This is
less probable mathematically than having just one X-chromosome missing the gene.

21) Light colours absorb less heat therefore these are not heated as much as the black
colour.
Ans: Dark colours do not exactly absorb more heat, but they do convert a higher percentage
of light into heat. In the sun with a dark coloured shirt it gets hot, where a lighter coloured
shirt would not get nearly as hot. This is due to the amount of light being absorbed by the
colour. The lighter the colour the smaller is the range of visible light being absorbed and
converted into heat. White objects reflect all visible light, where black objects absorb all
visible light.
22) Rain water is more fertile than water from tube well.
Ans: Rain water is more fertile because it contains many salts and nitrogen dissolved from
the atmosphere.
23) The manhole covers are generally round.
Ans: Manholes, which interconnect underground sewerage pipes, and serve as a point of
entry for cleaning the pipes, are located at every major sewer pipe junction, and are capped
with round manhole covers. The reason for the circular construction of these covers is,
quite simply, that covers of any other shape would fall through the manholes by virtue of
their varying diameters. Circular manhole covers do not vary in width, or in diameter, as is
the case with these other shapes, thus remaining in place despite the street traffic running
roughshod over them.
24) Clothes of a moving dancer bulge.
Ans: The clothes of a moving dancer bulge outside due to the centrifugal force which tends
to move away from the centre.
25) People are advised not to stand near fast moving train.
Ans: One should not stand beside a fast moving train because of the strong pressure of air
which carries along. A man can fall in this pressure.
26) The image of a tree is inverted on the bank of a lake.
Ans: The water of lake acts as a mirror. According to the laws of light, mirror forms inverted
images.
27) Polar star is always seen in the north.
Ans: It is because the Polar Star (North Star) is closest to the location of the celestial North
Pole.
28) We never see birds urinating.
Ans: The birds do not have a urinary system like other living beings which possess urinary
excretory organs. In the birds the urine is excreted from body without special organs.
29) Pasteurized milk has more nourishment than the ordinary boiled milk.
Ans: Pasteurized milk is obtained by heating milk at a temperature of 60 degree Celsius for
30 minutes. In this way the TB bacteria are killed without damaging the milk protein. Thus
pasteurized milk has more nourishment than ordinary boiled milk.
30) Bees die when they sting human being.
Ans: Their stingers are actually ovipositors, tubular structures extending from the
abdomen that sometimes contain eggs. When the barbed stinger is left inside the victim, the
honeybee mortally tears her abdomen in the process. They leave their stingers in the wound
with a tiny venom sac attached. Fortunately, only about one out of a hundred people are
allergic to bee sting, but allergic reactions can be very serious.
31) Cloudy nights are usually warmer than the clear ones.
Ans: The clouds serve as a barrier and prevent the loss of heat. Thus the warm temperature
is maintained.
32) Why do some people snore?
Ans: Some people snore during their sleep because the breathing action produces sound.
This is so because the pharynx or the windpipe offers resistance to the air taken in or
expelled.
33) Why do we sometimes sleep walk?
Ans: Sleep walk is a sort of disorder of sleep in which a person starts walking during his
sleep. The sleeper walks and performs complex activities automatically without regaining
consciousness.
34) Climbers bend forward while climbing mountain.
Ans: While climbing a mountain, a climber bends his body forward in order to keep the
centre of gravity of his body within two thirds portion. According to this principle the Pisa
Tower is not falling.
35) Why climbers get their food by climbing on other trees?
Ans: The climbers are mostly parasites and they cannot manufacture their food. Therefore,
they climb on other trees and get food from them.
36) Mars is called red planet.
Ans: Mars is called the red planet because its colour is red due to the desert like surface.
37) Vitamin D is the essential component of the body.
Ans: Vitamin D is necessary for body because it is essential for bone formation and retention of
calcium in the human body. Vitamin D also protects the teeth.
38) The weight of the object is less at the equator than at the poles.
Ans: The weight of an object is the product of mass and force of gravity. The equatorial diameter is
more than the polar diameter. Thus, the force of gravity is more at the poles and the weight is more
there.
39) The dogs pant, the birds open their mouth and the elephants move rapidly their ears.
Ans: All of them do not sweat; they use the above mentioned mechanisms to cool themselves.
40) A geostationary satellite appears standstill to a viewer on the equator of earth.
Ans: Because the distance remains the same.
41) Why do the stars twinkle?
Ans: The light from the stars travels through different layers of space of varying densities.
Therefore, the light rays deviate from their original path. Further, these layers are not stationary
but keep on moving. This leads to the twinkling of stars.
42) On what days do we have equal days and nights all over the world? And why?
Ans: On 23 September and 21 March we have equal days and nights all over the world. This is so
because on these days, the rays of the sun fall vertically on the equator at noon. Both the poles
receive equal rays of the sun. As a result, exactly one-half of each hemisphere receives the sun’s
rays. This makes day and night equal.
43) Every fourth year has 366 days. Explain.
Ans: One revolution of the earth around the sun takes 356 days and 6 hours. But we
consider a year as consisting of only 365 days and ignore 6 hours. In four years the
difference becomes as much as 24 hours or one day. Hence, to every fourth year we add one
day. That year of 366 days is known as leap year.
44) Why are igneous rocks called primary or parent rocks?
Ans: Igneous rocks are formed when the molten material from volcanoes gets solidified. This
material is liquid, hot and sticky which moves towards the surface through cracks and joints. All
other rocks derived from these rocks. Hence, they are called primary or parent rocks.
45) Why are the areas lying between the Arctic Circle and the North Pole in the Northern?
Hemisphere and the Antarctic Circle and the South Pole in the Southern Hemisphere very
cold?
Ans: These areas are very cold because the sun does not rise much above the horizon. Therefore, its
rays are always very slanting which emit minimum heat. These areas being very cold are called
Frigid Zones.
46) Why are the three hot regions of the world-equatorial forests, savannah lands and hot
deserts-not found in Europe?
Ans: The three hot regions of the world-equatorial forests, savannah lands and hot deserts-are not
found in Europe because Europe is the only inhabited continent situated entirely outside the
tropics.
47) Why is the lowest layer of the atmosphere in contact with the earth’s surface, the
warmest?
Ans: The lowest layer of the atmosphere in contact with the earth’s surface is the warmest because
the atmosphere is heated mainly from the below.
48) Why does the temperature above the ocean and land masses vary even on the same
latitude?
Ans: Temperature above the oceans and land masses varies even on the same latitude because of
the differential heating of land and water, i.e., land mass is heated and cooled more rapidly and to a
greater degree than water.
49) Why are marine animals able to live at great depths than marine plants?
Ans: As marine animals do not depend upon sunlight for their survival, they are able to live at great
depths where there is permanent darkness.
50) Why do trees of coniferous forests possess needle-like leaves?
Ans: The needle-like leaves limit transpiration and thus enable conifers to grow in the drier areas.
51) Why do equatorial forests appear evergreen?
Ans: In equatorial forests trees often shed a few leaves or shed their leaves seasonally, but most of
the trees retain their leaves for most of the time so that the forests appear evergreen.
52) Why is petroleum often called black gold?
Ans: Petroleum is often called black gold because of its great demand in the modern industry and
for domestic use. It provides fuel for heat and lighting, lubricant for machinery a nd raw material for
a number of industries.
53) Why are the kangaroos called marsupials?
Ans: Marsupial means broad-pouch. Since kangaroos have a pouch-like fold of skin near the
stomach in which they carry their young ones, they are called marsupials.
54) Why is platypus considered a strange animal?
Ans: Platypus is a strange animal because it is an animal-bird that survives under water, walks on
the ground and digs tunnel under the ground. It is a four-legged animal that lays eggs like a bird. It
is found in Australia.
55) Why is a person in moving vehicle thrown forward when the vehicle stops suddenly?
Ans: A person in a moving vehicle is in a state of motion. When the vehicle suddenly stops his body
tends to remain in a state of motion due to inertia and he is thrown forward.
56) Earth is continuously pulling moon towards its centre. Why does not the moon fall on to
the earth?
Ans: it is so because the gravitational attraction of the earth provides the necessary centripetal
force to the moon for its orbital motion around the earth due to which the moon is revolving
around the earth.
57) Which of the two-glass or rubber is more elastic and why?
Ans: Glass is more elastic than rubber because for a given applied force per unit area, the strain
produced in glass is much more than that produced in rubber.
58) Animal like camel can easily walk in the desert sand while other animals like donkeys,
dogs and horses cannot. Explain.
Ans: The camel has very broad and large feet. As a result of the large surface area in contact with
the ground, it exerts less pressure on the sand and sinks only slightly in it. Other animals have
smaller feet which exert more pressure on the sand. As a result, they sink more in the sand and
cannot walk easily in desert.
59) Why does a small quantity of liquid assume spherical form?
Ans: A small quantity of liquid assumes a spherical form due to surface tension which tends to
reduce the surface area. A given mass will acquire minimum surface area if it assumes a spherical
shape.
60) Why does an iron needle float on clean water but sink when some detergent is added to
this water?
Ans: Due to surface tension, the free surface of liquid at rest behaves like a stretched membrane.
When an iron needle floats on the surface of clean water, its weight is supported by the stretched
membrane. When some detergent is added to this water, its surface tension decreases. As a result of
it, the stretched membrane on the surface of water is weakened and is not able to support the
weight of needle. Hence the needle sinks in such water.
61) Why is cooking quicker in a pressure cooker?
Ans: The boiling point of water depends upon the pressure on its surface. Steam produced inside
the cooker builds up pressure thereby raising the boiling point of water, which results in quick
cooking.
62) Why does steam cause more severe burns than boiling water?
Ans: The amount of heat (latent heat) possessed by steam is much greater than the amount of heat
possessed by water at the same temperature. Therefore, steam causes more severe burns than
boiling water.
63) Why does ice not melt readily when salt is sprinkled over it?
Ans: When salt is sprinkled over ice, some of it dissolves. As dissolution of the salt is accompanied
by absorption oh heat. The temperature of the system falls below 0 degree Celsius. Hence, ice does
not melt readily.
64) It is difficult for firemen to hold a hose, which ejects large amount of water at a high
velocity. Why?
Ans: the water which comes out of the fireman’s hose carries large momentum as its velocity is very
high. The equal and opposite reaction force pushes the fireman backwards with a great speed
satisfying the law of conservation of momentum. As a result, it is difficult for the fireman to hold the
hose.
65) In the outer space astronauts talk to each other through radios. Why?
Ans: sound waves need a material medium for its propagation. There is no air in space and hence,
sound waves cannot travel. However, radio waves can travel through space. The astronauts can see
each other because light, like radio waves, can travel through vacuum.
66) Sonar scanners are used by doctors. Explain.
Ans: sonar scanners send out ultrasonic waves, which are reflected by body tissue and organs.
From the pattern of reflections, a computer can build up an image of the internal structure which is
vital for diagnosis.
67) Why the flash of lightning is seen before the sound of thunder is heard?
Ans: the velocity of light is much greater than that of the sound. Therefore, flash of lightning is seen
before the sound of thunder is heard.
68) Bats have poor eyesight but are able to home their prey with great accuracy. Also,
dolphins can avoid fishing nets and can detect fish at night. Explain
Ans: Bats emit high frequency (1, 20,000 Hz) sound waves and listen with their sensitive ears for
any echoes. From the time taken to hear the echo and from the nature of sound received. Bats are
able to estimate the distance and the type of surroundings. This process is known as echolocation.
Same process is used by the dolphins.
69) When low flying aircraft passes overhead, we sometimes notice a slight disturbance on
our TV screen. Why is it so?
Ans: a low flying aircraft reflects TV signal. Due to the interference between the direct signal and
the reflected signal, there is disturbance on the TV screen.
70) In automobiles, why are convex mirrors used to see the traffic from behind?
Ans: Convex mirrors are used in automobiles because they form erect and diminished images of the
object. Thus, it helps the drivers to get a wider field of view of the traffic coming from behind.
71) Why is mirage formes in the deserts?
Ans: A mirage is formed owing to total internal reflection. To the observer at a distance, the
reflected image of the object appears behind the reflecting surface, as if the object were in front of
it, but actually it is just an illusion.
72) What will be the colour of grass in blue light?
Ans: Grass will appear blackish in colour in blue light because it has the property of absorbing all
other colours except its own colour. The blue rays falling on grass will be absorbed by it, and it will
appear dark coloured.
73) A bird perches on a bare high power line and nothing happens to it. A man standing on
the ground touches the same line and gets a fatal shock. Why?
Ans: When bird perches on a live high power line, no current passes through the body of bird
because there is no potential difference between live wire and the body of bird as the potential of
bird’s body is the same as that of wire. When a man standing on the ground touches the same wire
then due to a large potential difference between his hands and feet, a large current flows through
his body to the earth.
74) During lightning it is safest to be inside a car rather than under a tree or in the open.
Give reason.
Ans: When a person is in the open or under the tree, the lightning passes through his body to the
earth. On the other hand, for a person inside a car, the car provider shielding and the electric field
inside the car is zero, thus lightning does not affect the person inside it. The lightning actually
passes through the metallic body of the car to the earth without affecting the person sitting inside it.
75) Why is earthing desirable for electric appliances?
Ans: Earthing helps the current move into the earth in the event of short-circuit, without giving a
shock to the user.
76) Why does a perspiring man feel relief when air flows by his side?
Ans: The air flowing by the side of a perspiring man quickens the pace of evaporation of
perspiration from the body of that person, and the resultant loss of heat from his body causes the
cooling sensation which provides relief to him.
77) Why is magnet always made of soft iron?
Ans: Magnet is always made of soft iron because ‘magnetization’ and ‘demagnetization’ both are
possible in soft iron.
78) Why are telephone wires between two poles kept loose?
Ans: Telephone wires are kept loose between two poles so that they are protected from being
broken due to expansion and contraction caused by the change of temperature in summers and
winters.
79) X-rays penetrate through the flesh but not through bones. Why?
Ans: The penetrating power of X-rays depends upon the potential difference between the cathode
and the anode of X-ray tube. The X-rays produced can penetrate through light element like flesh of
human body but they are unable to penetrate through heavier elements like bones.
80) What is a black hole? Why is it called so?
Ans: A black hole is a super dense planetary material formed due to the death of a star of mass more
than five solar masses. It is called black hole because any particle or photon approaching its surface
is just swallowed by it. It appears black, as radiation is neither emitted nor reflected by it.
81) Why do water pipes burst in severe cold winters?
Ans: Water freezes in pipes during winters, when the temperature goes below 0 degree Celsius (i.e.,
freezing point of water). It expands and in the process exerts pressure on the water pipes, thereby
sometimes bursting them.
82) Most aircrafts and ships have their front shape pointed. Why?
Ans: The shape of many objects, viz. aeroplanes, rockets, ships, etc. moving through air or water, is
designed in such a way that friction can be reduced between the objects and air/water. Such type of
body is known as streamlined and the process is known as streamlining.
83) An athlete runs some distance before taking jump, why?
Ans: An athlete runs a certain distance before actually jumping in order to increase his speed, and
thereby, his inertia of motion. This increased inertia of motion enables him to jump a longer
distance.
84) It is difficult to drown in the Dead Sea. Why?
Ans: The water of Dead Sea has a salt content of 27%. Therefore, its density is much greater than
that of ordinary sea water and it also offers a greater upthrust. Hence, the body weighs less than an
equal volume of Dead Sea water and is thus, able to float.
85) Why aquatic animals have soft skeleton unlike those of the terrestrial animals?
Ans: The density of animals and fish living in water is almost the same as the density of water.
Therefore, their weight is almost completely balanced by buoyancy. That is why they do not need
massive skeleton like those of terrestrial animals.
86) Why does a swimming pool appear less deep than it really is?
Ans: When rays of light start from the bottom of a pool and travel from water to air, they are
refracted away from the normal because they travel from a denser medium to a rarer medium. As a
result, a virtual image of bottom is formed above the bottom. Hence, a swimming pool appears less
deep than it really is.
87) Why is electrical wiring in parallel better?
Ans: electrical wiring in parallel is better because all the lines will have the same potential
difference and if one line gets fused the other lines remain unaffected.
88) It is easier to swim in sea water than in river water. Explain.
Ans: The density of sea water is more than that of the river water. Therefore, the weight of sea
water displaced by the swimmer is more. Thus, buoyant force of up thrust on the swimmer
increases, making it easier to swim in sea water.
89) A cold compress is applied on the forehead of a person suffering from high fever. Why?
Ans: Evaporation causes cooling. As the water evaporates, it absorbs heat from the forehead and
helps in reducing the temperature.

90) A man with a load his head jumps from a high building. What will be the load
experienced by him.
Ans: Zero, because the acceleration of his fall is equal to the acceleration due to gravity of the earth.

91) Why is spring made of steel and not copper?
Ans: The elasticity of steel is greater than that of copper.

92) Why is it easier to spray water to which soap is added?
Ans: Addition of soap decreases the surface tension of water. The energy for spray is directly
proportional to surface tension.

93) A piece of chalk when immersed in water, emits bubbles. Why?
Ans: Chalk consists of pores forming capillaries. When it is immersed in water, the water begins to
rise in the capillaries and air present there is expelled in the form of bubbles.

94) Why does a liquid remain hot or cold for a long time inside a thermo flask?
Ans: Because of the presence of air, which is poor conductor of heat, in between the double glass
walls of a thermos flask?

95) Why is the boiling point of sea water more than that of pure water?
Ans: Sea water contains salts and other impurities with different points which jointly rise its boiling
point.

96) Why is it recommended to add salt in water while boiling grams?
Ans: By addition of salt the boiling point of water gets which helps in cooking.

97) Why is soft iron used as an electromagnet?
Ans: Because it remains magnetic only till the current passes through the coil and loses its
magnetism when the current is switched off (principle of electric bells)

98) Why does ink leak out of a partially filled pen when taken to a high altitude?
Ans: As we go up the pressure and the density of air go on decreasing. Partially filled pen leaks
when taken to a higher altitude because the pressure of air acting on the ink inside the tube of the
pen is greater than the pressure of air outside.

99) Why does some liquids burn while others do not?
Ans: A liquid burns if its molecules can combine with oxygen of the air with the production of heat.
Hence, oil burns but water does not.

100) Oil and water do not mix. Why?
Ans: i) Molecules of oil are not bigger than that of water and therefore do not mix easily. ii)
Molecules of water are polar, i.e. they have opposite charges at two ends whereas oil molecules do
not; as a consequence they tend to stay away from water molecule.

Do bestow your precious words at the end...

Regard..
Ali Baloch
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Old Saturday, January 10, 2015
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nice dear also post some more reasons
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More Interesting Reasons....

1. What is nuclear winter?

2. How is heat suddenly generated to the extent of 50,000 Fahrenheit during lightning?

3. How is the light produced when an object is burnt?

4. Diamond is a good thermal conductor. But it is an excellent electrical insulator. How?

5. What is the difference between dial up and broadband Internet connections?

6. When a lighted matchstick is shown before another light source, the shadow of the matchstick is formed on a screen but not the shadow of the flame. Why is it so?

7. Why are fishes not able to survive in distilled water?

8. Why do eggs become hard on boiling?

9. What is the powder like material found on the wings of butterflies? What is its use?

10. Why do our eyelashes and eyebrows never continue to gow unlike hair on our head?

11. Jackfruit is the only fruit that grows also from the tree trunk. What makes this possible?

12. How does one control the movement of hot air balloons?

13. How does remote control in TV work?

14. Why is the power of a loudspeaker expressed in watts?

15. What makes the earth rotate?

16. What is the difference between a sodium vapour lamp, Which gives out a yellowish colour illumination, and a mercury vapour lamp that gives out a white colour illumination?

17. Both Infrared and Microwave bands are invisible to the human eye. Then how are IR and microwave images from remote sensing satellites printed? How do they substitute the wavelenghts?

18. How does lightning affect TVs?

19. Soaps come in different colours. But why is soap's lather always white in colour?

20. Is the mosquito a carrier of AIDS causing virus?

21. Does the change in mother's food affect the baby?

22. What is Radio Therapy?

23. Since clouds contain tiny water droplets, why are rainbows not permanently present?

24. How does the solar wind affect Earth?

25. How do icebergs form?

26. Why is fire hot?

27. How is sex determined in dioecious plants?

28. How does the camel walk in the desert easily?

29. How can we test the purity of honey?

30. What is meant by ozonised mineral water?

31. Why do lips become dry during winter?

32. Why do houseflies rub their front legs together?

33. How does a lightning arrestor work?

34. Like ordinary paints do metallic paints also fade?

35. What is the difference between tv screen and computer monitor?

36. What is the pH of rainwater? Is the pH suitable for drinking?

37. In the past, why was injection administered in the stomach for dog bite?

38. How does scratching cure itching sensation?

39. Why does sea water not erode coastal areas in all places?

40. Do animals also have blood groups like humans?

41. What is Computer Simulation Technique?

42. How does Ballast-Less Track provide safe travel?

43. How do certain species of birds such as humming birds, terns, gulls and kestrels remain in the air without a forward motion?

44. How is carbon dioxide removed from blood before it is exhaled?

45. Why is the Earth's core hot? What caused it to heat up? Is it still heating, or now cooling?

46. Why does rain come in drops and not in a continuous stream?

47. What are polaroid sunglasses made of?

48. Why is the @ symbol used in an email address?

49. How does the solar wind affect Earth?

50. How do touch screens work?

51. Does frequent switching on/off of a fluorescent lamp reduce its life?

52. How is a ventriloquist able to throw his voice?

53. What is the peculiar smell of the earth after the first shower?

54. How does a rechargeable battery work? What is the life of such batteries and how are they different from ordinary batteries?

55. Why is fuel used in airplanes different from those used in motor vehicles?

56. Why does an egg (with the shell) burst when cooked in a microwave oven?

57. How does a compact fluorescent lamp consume less electricity than conventional fluorescent lamps and bulbs?

58. What causes milk to rise up when we boil it?

59. Why are we unable to see through a frosted glass?

60. Why does our mouth stink after a night's sleep despite brushing before going to sleep?

61. How does wheat flour become malleable and elastic when mixed with water?

62. How do raw mangoes and bananas become ripe when treated with chemicals?

63. What is the powdery deposit found on some fruits like grapes? What is its use?

64. How is the speed of a computer measured?

65. What is magnetic levitation? How does it work?

66. Why is it easier to tear wet paper and not dry paper?

67. How are some insects able to walk on the surface of water?

68. Why do wounds heal slowly in diabetics?

69. How do pharmaceutical companies arrive at expiry dates for medicines?

70. What is the difference between computer monitor and colour television?

71. How are snake pits formed?

72. How does a compact fluorescent lamp consume less electricity than conventional fluorescent lamps and bulbs?

73. Why does it take a longer time to copy a file to a computer than delete it?

74. A hen lays an egg every day. From where does it get the calcium required to make the eggshell?

75. Why do doctors prescribe some medicines to be taken before and some after food?

76. Why does a mushroom shaped cloud form after a nuclear bomb explosion?

77. Is sweat examined as a clinical sample like blood, urine and sputum?

78. Why do pregnant women like eating tamarind and raw mangoes?

79. Why does the reception of a transistor become clear when the antenna is touched?

80. Why are antibodies not produced against sperms by the female's immune system?

81. Why are we unable to walk straight and tend to lose our balance when we walk with our eyes closed?

82. Why are diesel driven vehicles noisy?

83. Why does a single cross hybrid give better yield compared to double cross hybrid?

84. Why does a battery operated transistor make noise when a nearby tube light is switched on?

85. Why do we see rainbow colours on a CD?


For the answer of All above Reasons, Click on this link.....http://www.scholarshipsinindia.com/scientificfacts.html

Your Appreciation ll be highly entertained...

Regards...
Ali Baloch
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Old Sunday, January 11, 2015
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Smile 7 Simple Questions You Won't Believe Science..

One advantage of living in the information age is learning new things every day. Even more interesting is when we learn stuff that we thought we already knew but apparently didn't, like the fact that the sun is a sphere. Yep, science just found that out in February 2011. Next they're going to tell us that they just figured out whether the chicken or egg came first. Actually ....

#7. Which Came First: The Chicken or the Egg?


If you're anything like us, you probably spent a good part of your college years in a Denny's booth debating the universe's biggest mysteries, like how rad exactly is Dave Matthews Band live? And will baby tees and chunky Rachel layers ever go out of style? Eventually, we all arrived at the age-old dilemma that asks which came first: the chicken or the egg? And more importantly, who gives a crap? Well, Stephen Hawking, for starters, weighed in on the debate. He said it had to be the egg, and since Stephen Hawking majored in Super Genius at Mega Whiz University, we could probably just take his word for it.

What We Just Found Out

It was the chicken. SUCK IT, HAWKING! HOW DOES IT FEEL TO BE A FRIGGIN IDIOT???


Via Wikimedia Commons

Not such a big man now, are you, Hawking?

In the summer of 2010, British researchers cracked the eneggma when they discovered that the protein necessary to create the eggshell was fowlnd exclusively in the ovaries of the chicken. So the chicken had to come first, because the eggshell can't be made without that protein. Where did the chicken come from? Maybe a hybrid dinosaur called a chickosaurus. We don't know. We weren't there.


Via James Gurney

Bwok bwok ROAR!

The protein ovocledidin-17 controls the eggshell crystallization process, and without it, the shell couldn't form at all. Scientists weren't just trying to settle a bet between Hawking and some other scientist, either. Understanding what eggshells are made of has some pretty incredible real-world applications, such as strengthening synthetic bones or stopping freaking global warming.

One of the newest ways scientists are trying to tackle global warming is by capturing all that excess CO2 that cars and hairspray canisters have been farting into the air, then storing it until we figure out how to make flat-screen TVs out of it. Understanding the protein that makes eggs form can help us crystallize carbon dioxide into limestone, presumably so we can then dump it into the ocean. Because what harm could possibly come from putting genetically modified rocks into the ocean?


Via summeroflovecraft.com

#6. Why Hair Turns Gray


The only people who are 100 percent cool with being grey/gray are Jennifer and Macy. The rest of us are willing to spend $42.5 billion a year covering it up. That's more than Americans spend every year on diet products, and look at how fat we are. Even women so decrepit that they're one wrinkly foot in the already-dug grave feel compelled to cover their gray hair, as if a little bleach is all it takes to make you forget they're a million years old.


Via tn.nova.cz

Gentlemen prefer blondes! Like me!

Gray hair is one of those things that just sort of makes sense. The ink cartridges in our printers run out when they get old. Why wouldn't the ones in our heads run out of color, too? They're pretty much asking for it, since they keep printing everything in the same color.

What We Just Found Out

Actually, it's just the opposite. When we go gray, our bodies are bleaching our hair from the inside out.

Everyone's body makes hydrogen peroxide naturally. The buildup eventually gets so colossal that it blocks the melanin -- your body's natural hair dye. Without that melanin, the hairs turn gray, then eventually white. And just like that, we're old.


Getty

It apparently happened to Steve Martin at the ripe old age of 4.

So how did we just figure this out? After examining cell cultures of hair follicles, researchers found that aging adults have lower levels of an enzyme that breaks up hydrogen peroxide into water and oxygen. Basically, your scalp is the site of a battle between good and evil every day of your life. Right now, bleached barbarians are invading your hair from the inside of your scalp. Those of you whose bodies still produce colored hair have soldiers guarding each hair follicle and repelling the barbarians successfully. However, one day, your guards will decide they're too old for this shit and up and retire. Now the Ostrogoths reign over your follicular empire, and your glorious colored-hair civilization is over.


And they never, ever give up.

The good news is that knowing how the process works goes a long way toward knowing how to stop it from happening altogether. Imagine a world where you don't have to go gray if you don't want to, where your grandparents and great-grandparents keep the hair of their youth, where you have to get up close to tell whether someone is bangable.


Getty

Grandma?

#5. The Moon: What's Up With That?


Unless you're a Druid, a poet, a werewolf or some heinous combination of all three, you probably don't spend much time thinking about the moon. We notice when it's there, forget about it when it's hidden and occasionally laugh at the suckers who used to think it was made out of cheese.


Photos.com

Oh, and goths. Goths love them some moon.

Here's the thing, though. Despite the fact that the moon is obviously the closest thing to the Earth in the universe, or that we've been on it, up until fairly recently, we knew surprisingly little about it. Why is one side of the moon pockmarked while the other is smooth? How'd it get there? What's it made of? An annoying-enough person could have argued that the whole cheese theory technically could have been right, and up until recently, scientists would have had to back down. Sure, they had some good guesses, just like we've got guesses as to why starving people have big fat bellies (they're tricking us for sympathy). That doesn't mean they're right.


Getty

You dirty, manipulative bastards.

What We Just Found Out

No one has been on the moon for almost 40 years, so it's not like we could just pop up there and start digging and sticking thermometers into its craters. Fortunately, astronauts left seismometers on the moon during the Apollo missions that transmitted moonquake data back to Earth until 1977. Recently, a professor and a graduate student at Arizona State University took those numbers and applied a new method of analysis to them called array processing. By layering seismic recordings together and studying them at the same time, they were able to detect very faint signals they couldn't hear before. Then they used those signals, or "echoes," to map out what was going on beneath the moon's surface using the same techniques geoscientists use to figure out what's going on beneath the Earth's surface. Next, they high-fived each other and screamed, "Bla-DOW! Science!"


Getty

Yay! Time to break out the orange juice and people clothes!

The data told Professor Clever and his student minion that the moon has a solid, iron-rich core, just like the Earth's, and that the core is surrounded by a liquid iron outer core, also just like the Earth's. Both the Earth's core and the moon's core are made of iron, nickel and light elements like sulfur.

This is important, because it supports the prevalent theory of how the moon got there, which is that a Mars-size body hit Mother Earth, which chunked Baby Earth fetuses out into space, which eventually accelerated and melded together to make the moon. Sure, it doesn't explain where cheese comes from, but it's a start.

#4. Pruney Fingers


Remember the first time you noticed how your hands got wrinkly when you stayed in the bathtub too long? And how you assumed the wrinkling was caused by an aging curse cast by your neighbor, who was clearly a voodoo queen because she was the only woman in town who wore a turban? And remember how your mom explained that it was sitting in a bathtub for an hour and a half, not black magic, that gave you Shar-Pei hands? Turns out your mom was talking out of her ass.


Photos.com

She was trying to cover a terrible, terrible secret.

Not only did science not completely understand why you got pruney fingers in the bathtub, it didn't know why your skin didn't disintegrate after taking on so much water. This, apparently, was a real conundrum to scientists. They looked at your skin under a microscope, worked up some advanced mathematical models and decided that your skin should just fall apart like crepe paper in the rain every time you take a bath.

What We Just Found Out

Math. Math is under our skin, doing its mathy work, keeping our skin intact and unmelted.

Take a look:


Via wired.com

That's a model of a gyroid, which is a geometrical shape found all over the natural world. Mathematicians think that fibers of keratin in our skin are actually woven into this shape as well, which is important, because it means the skin can expand but keep its structure because the fibers have so many connections to one another. With this pattern, the fibers can "swell to fill a volume seven times greater than its original shape."

That's what's happening when your skin wrinkles. It's absorbing water, which makes it grow in volume. Since the rest of your hand is still the same size, your skin begins to wrinkle the same way a glove would if it was too big for your hand. As unnerving as it might be to think that your skin is getting too baggy for the rest of your body, it's better than the alternative.


Getty

Most geometric models, when asked to grow in volume, just break up. To illustrate this, try taking a bath in a tub made of corrugated cardboard. Not so easy, is it? That's because unlike your skin, that cardboard is woven together in a gyroidless pattern, which falls apart.

As scientists learn more about gyroids, they might be able to use the pattern for synthetic skin, bandages, bulletproof vests and more weather-resistant housing for the homeless population.
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  #5  
Old Sunday, January 11, 2015
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I read first two answers nd the last one as well, and seriously none of the three was upto the mark. These are less satisfactory answers and I would admonish the readers not to follow these.. I'm not offending, so plz don't mind. .
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@Raviz Bro... Do you think these are not essential? I would say might be you are not in this stage to know the value coz your in outskirt, when you ll be inside surely you know the value of words.... see birds eye view these Questions are not worthy

5. What is the difference between dial up and broadband Internet connections?

6. When a lighted matchstick is shown before another light source, the shadow of the matchstick is formed on a screen but not the shadow of the flame. Why is it so?

7. Why are fishes not able to survive in distilled water?

8. Why do eggs become hard on boiling?

9. What is the powder like material found on the wings of butterflies? What is its use?

10. Why do our eyelashes and eyebrows never continue to gow unlike hair on our head?

11. Jackfruit is the only fruit that grows also from the tree trunk. What makes this possible?

12. How does one control the movement of hot air balloons?

13. How does remote control in TV work?

14. Why is the power of a loudspeaker expressed in watts?

15. What makes the earth rotate?

16. What is the difference between a sodium vapour lamp, Which gives out a yellowish colour illumination, and a mercury vapour lamp that gives out a white colour illumination?

17. Both Infrared and Microwave bands are invisible to the human eye. Then how are IR and microwave images from remote sensing satellites printed? How do they substitute the wavelenghts?

18. How does lightning affect TVs?

19. Soaps come in different colours. But why is soap's lather always white in colour?

20. Is the mosquito a carrier of AIDS causing virus?

21. Does the change in mother's food affect the baby?

22. What is Radio Therapy?

23. Since clouds contain tiny water droplets, why are rainbows not permanently present?

24. How does the solar wind affect Earth?

25. How do icebergs form?

26. Why is fire hot?

27. How is sex determined in dioecious plants?

28. How does the camel walk in the desert easily?

29. How can we test the purity of honey?

30. What is meant by ozonised mineral water?

31. Why do lips become dry during winter?

32. Why do houseflies rub their front legs together?

33. How does a lightning arrestor work?

34. Like ordinary paints do metallic paints also fade?

35. What is the difference between tv screen and computer monitor?


If you read dear so it doesn't mean that every body knows..... T
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  #7  
Old Tuesday, January 13, 2015
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Quote:
Originally Posted by Humble Ali View Post
Hello friends these are 100 Important Scientific Questions, which i gone through in two days, please you all must opt this practice try to commit to memory in a day....


2) The Sun appears red at sunset and sunrise. Why?
Ans: The sun appears red at the time of sunset and sunrise due to the scattering of light by small
particles of dust or smoke near the surface of the earth. The light travels relatively without
hindrance that is why the sun appears red at the time of sunset and sunrise.
Dust is not the reason "for redness of sun".Dust theory is 100 years old.

Blue light is scattered and spread being of short wavelength. (Though violet is shortest but it is absorbed by upper atmosphere and our eyes are less receptive to violet as well)
At evening even more blue light is scattered therefore red and yellow are reached.

Dust particles don't scatter but reflect the light, due to which "SKY" appears red at sunset.

Quote:
4) The sky from moon appears black. Why?
Ans: as the moon has no atmosphere, so the sky looks completely black when viewed from
the moon.
Same logic as that of Q2.
5) Roads are bent inwards on curves. Why?

Logic increase in "Friction" was not given. Rest was ok.


Quote:
8) It is not advisable to sleep under trees during the night.
Ans: During night the plants release carbon dioxide (CO2) which is a poisonous gas and
injurious to health. That is why it is not advisable to sleep under trees during night.
Add "respiration" of plants during night is increased relative to photosynthesis.

Quote:
10) Rainbow is produced in the sky after rainfall and sunlight.
Ans: After rain, many droplet of water travel in the atmosphere. When sun rays fall on these
droplets, dispersion of water occurs and droplets act as prism and produce a spectrum of
seven colours. That’s why a rainbow is seen in the sky after rain.
Add terms "wavelength" and "refraction"

Quote:
11) Milk is considered as an ideal food.
Ans: Milk is considered as an ideal food due to following reasons: a) It contains all constitute
of balanced diet. b) Milk contains fat. c) Milk has high nutritional value because it contains
proteins as well as minerals.
1. Fat 2. Protein 3. Lactose sugar 4. Minerals 5. Vitamins 6. Anti-Bacterial effect due to lactoferrin and lysozyme. 7. Antibodies for various diseases

Quote:
13) Goitre is common in hilly areas.
Ans: Goitre is common in hilly areas because there is deficiency of Iodine in
the water.
Add relative increase in Metabolism as well.


Quote:
20) Colour blindness is more common in men than women.
Write the terms "Allele", Heterozygous, Recessive and dominant genes.

Quote:
28) We never see birds urinating.
Ans: Urate a relatively less toxic substance, require very less amount of water as compared to Urea, the reason birds have adapted to have an vestigial, less developed or no urinary system, ostrich being an exception.

Quote:
29) Pasteurized milk has more nourishment than the ordinary boiled milk.
Ans: Pasteurized milk is obtained by heating milk at a temperature of 60 degree Celsius for
30 minutes. In this way the TB bacteria are killed without damaging the milk protein. Thus
pasteurized milk has more nourishment than ordinary boiled milk.
Milk protein not gets deformed completely after pasteurization.

Quote:
32) Why do some people snore?
Ans: Some people snore during their sleep because the breathing action produces sound.
This is so because the pharynx or the windpipe offers resistance to the air taken in or
expelled.
It's because during sleep, the air passage is narrowed and soft tissues hinders the passage of air.

Remaining corrections and additions. DIY.
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  #8  
Old Friday, January 30, 2015
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Post 85 Scientific Reasons

I have compiled 85 Scientific reasons / Questions answers ; you may download it by visiting below URL link.


http://www.datafilehost.com/d/a55ae267
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Old Monday, February 09, 2015
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Smile Scientific Questions

Here I have compiled 100 Important` Scientific Questions
Get this free download!
http://www.datafilehost.com/d/eb167527
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