Some Quick Science GK

No.	Question	Answer
01	The theory of relativity was propounded by	Albert Einstein
02	The principal metal used in manufacturing steel is	Iron
03	An altimeter is used for measuring	Altitude
04	Oology is the study of	Birds eggs
05	Radioactivity was discovered by	Henry Bacquerel
06	The metal used in storage batteries is	Lead
07	The instrument used to measure the relative humidity of air is	Hygrometer
08	Barometer was invented by	Torricelli
09	The unit of power is	Watt
10	Radium was discovered by	Marie and Pierrie Curie
11	The existence of isotopes was discovered by	Frederick Soddy
12	Dynamo was invented by	Michael Faraday
13	The nuclear reactor was invented by	Enrico Ferni
14	The law of gravitation was propounded by	Sir Isaac Newton
15	Crescograph was invented by	J.C.Bose
16	Crescograph is used to measure the	Rate of growth of a plant
17	Galileo’sfirst scientific discovery was	Pendulum
18	Microscope was invented by	Aaton Van Leewen Hock
19	The scientist who is known as father of modern biology is	Aristotle
20	The first person to see a cell under microscope was	Robert Hooke
21	The smallest flowering plant is	Worffia
22	The four blood groups were discovered by	Karl Landsteiner
23	Sodium was discovered by	Sir Humphry Davy
24	The atomic number of oxygen is	Eight
25	The basic building blocks of proteins are	Amino acids
26	The botanical name of the cotton plant is	Gossipium Hirsutum
27	An Electroscope is used to	Detect charges on a body
28	The unit of loudness is	Phon
29	An ammeter is used to measure	Electric current
30	Plant that eat insects are called	Insectivorous plants
31	Fruits that are formed without fertilization are called	Parthenocarpic
32	Plants that flower only once in their lifetime are called	Mono carpic
33	The botanical name for rice is	Oryza Sativa
34	Penicillin is obtained from	Mould
35	The largest tree in the world is	Seguoia Gigantica
36	Herpetology is the study of	Reptiles
37	Entomology is the study of	Insects
38	Ornithology is the study of	Birds
39	Ichtyology is the study of	Fishes
40	Osteology is the study of	Bones
41	The botanical name for brinjal is	Solanum melongenal
42	The botanical name for onion is	Allium Cepa
43	The study of sound is called	Acoustics
44	The study of heavenly bodies is called	Astronomy
45	The study of tissues is called	Histology
46	Electric Lamp was invented by	Thomas alva Edison
47	The fear of crowd is called	Ochlophobia
48	The fear of books is called	Bibliophobia
49	The fear of going to bed is called	Clinophobia
50	The symbol of gold is	Au
51	The symbol of sodium is	Na
52	The symbol of Sr stands for	Strontium
53	The symbol Rb stands for	Rubidium
54	The symbol Md stands for	Mendelevium
55	Calcium sulphate is commonly called	Plaster of Paris
56	Sodium carbonate is commonly called	Washing Soda
57	Sodium chloride is commonly known as	Common Salt
58	The chemical name of Chloroform is	Trichloromethane
59	The chemical name of baking powder is	Sodium bicarbonate
60	The chemical name of bleaching powder is	Calcium hypochlorite
61	The formula HCL stands for	Hydrochloric Acid
62	The formula H2SO4 stands for	Sulphuric Acid
63	The formula CHCI3 stands for	Trichloromethane
64	The formula H2O2 stands for	Hydrogen peroxide
65	A fungus which can only survive on other living organisms is called	Obligate Parasite
66	A plant which lives in the dark is called	Scotophyte
67	A plant adapted to live in dry places is called a	Xerophyte
68	A plant adapted for growth in water is called a	Hydrophyte
69	Bifocal lens was invented by	Benjamin Franklin
70	Cement was invented by	Joseph Aspdin
71	Laser was invented by	Dr.Charles H.Townes
72	Electromagnet was invented by	William Sturgeon
73	Rayon was invented by	Sir Joseph Swann
74	Thermostat is an instrument used for regulating	Constant temperature
75	The science of organic forms and structures is known as	Morphology
76	Phycology is the study of	Algae
77	Tata Institute of Fundamental Research was established in	1945
78	CSIR stands for	Council of Scientific and Industrial Research
79	ISRO stands for	Indian Space Research Organisation
80	The first human being to land on moon was	Neil Armstrong
81	The first Indian in space was	Rakesh Sharma
82	ISAC stands for	ISRO Satellite Centre
83	VSSC stands for	Vikram Sarabhai space Centre
84	The headquarters of ISRO is located at	Bangalore
85	VSSC is located at	Thiruvananthapuram
86	ISAC is located at	Bangalore
87	National Science Centre is located at	New Delhi
88	Central Tobacco Research Institute is located at	Rajahmundry
89	Indian Institute of Horticultural Research is located at	Bangalore
90	The Atomic Energy Commission was set up in	August 1948
91	The first IndianSatellite was	Aryabhatta
92	The first Indian Satellite was launched in the year	1975
93	ASLV stands for	Augmented Satellite Launch Vehicle
94	INSAT stands for	Indian National Satellite
95	The fear of women is known as	Gynophobia
96	The fear of men is known as	Androphobia
97	The scientist who developed the Quantum theory was	Max Plonck
98	The steam engine was invented by	James Watt
99	The botanical name of tea is	Camellia Sinensis
100	Logarithms were devised by	John Napier
101	The acid used in a car battery is	Sulphuric acid
102	The system for writing by blind people was invented by	Louis Braille
103	The parachute was used for the first time by	J.P.Blanchard
104	The German physicit who first demonstrated the existence of Radio waves was	Henrich Hertz
105	The instrument that records the intensity of earthquakes is	Seismograph
106	The laws of floating bodies was discovered by	Archimedes
107	The density of milk is measured by a	Lactometer
108	Fountain pen was invented by	L.E.Waterman
109	The instrument used to measure the pressure of gases is the	Monometer
110	Bhaskara I was a famous	Astronomer
111	The first atomic power station established in India was the	Tarapore Atomic Power Station
112	The role of heredity was demonstrated by	Mendel
113	The instrument used to measure the concentration of salt water is the	Salinometer
114	Spectroscopy is the study of	Anders John Angstrom
115	Dactylography is the study of	Finger Prints
116	A tangent galvanometer is used to study the	Strength of direct current
117	The fruit of Oak is called	Acron
118	ZETA stands for	Zero Energy Thermonuclear Assembly
119	The formula C6H5OH stands for	Phenol
120	Michael Faraday worked as an assistant under another scientist whose name was	Sir Humphry Davy
121	Vulcanised rubber was invented by	Charles Goodyear
122	The symbol Zn stands for	Zinc
123	The symbol He stands for	Helium
124	Celluloid was invented by	A.Parker
125	Glider was invented by	Sir George Caley
126	Safety matches was invented by	J.E.Lundstrom
127	Radio valve was invented by	Sir J.A.Fleming
128	Space Applications Centre is located at	Ahmedabad
129	Atomic Energy Commission is located at	Mumbai
130	Dynamics is the study of	Movements of bodies
131	Statics is the study of	Forces acting on bodies at rest
132	Mechanics is the study of	Forces acting on bodies
133	Zoology is the study of	Animal life
134	Botany is the study of	Plant life
135	Psychology is the study of	Human mind
136	The first American to orbit earth was	John H.Glen
137	The electro-cardiograph was invented by	William Einthoven
138	The molecular formula of cane sugar is	C12H22O11
139	A compound which contains only hydrogen and Carbon is called a	Hydrocarbon
140	The liquid used to preserve specimens of plans and animals is	Formalin
141	The law of segregaton was propounded by	Mendel
142	Auriscope is used to detect	Ear disorders
143	The three states of matter are	Solid,liquid and gas
144	The scientific name for blood platelets is	Thrombocytes
145	The response of a plant to heat is called	Thermotropism
146	The response of a plant to touch is called	Trigmotropism
147	The symbol Zr stands for	Zirconium
148	Nickel was discovered by	Cronstledt
149	Manganese was discovered by	Gahn
150	The common name for pottasium carbonate is	Potash
151	Bismuth was discovered by	Valentine
152	The biggest plant seed is	Cocodemer
153	Toxicology is the study of	Poisons
154	Virology is the study of	Viruses
155	Paleontology is the study of	Fossils
156	Calorimeter is used to measure	Quantity of heat
157	Chronometer was invented by	John Harrison
158	Stethoscope was invented by	William Stockes
159	Spinning frame was invented by	Sir Richard Arkwright
160	Al stands for	Aluminium
161	Gd stands for	Gadolinium
162	Ir stands for	Iridium
163	Bi stands for	Bismuth
164	The Chemical formula of sodium bicarbonate is	NaHCO3
165	The chemical formula of common salt is	Nacl
166	The chemical formula of washing soda is	Na2CO3,IOH2O
167	The chemical formula of lime soda is	CaCO3
168	The chemical formula of chloroform is	CHcl3
169	The study of grasses is known as	Agrostology
170	The study of antiquities is known as	Archaeology
171	The study of the duration of life is known as	Chronobiology
172	The study of bacteria is known as	Bacteriology
173	Nylon was invented by	Dr.Wallace H.Carothers
174	Electric razor was invented by	Jacob Schick
175	The symbol of silver is	Ag
176	The symbol of silicon is	Si
177	The symbol of titanium is	Ti
178	Calcium oxide is commonly known as	Quick lime
179	A deviation of light passing from one medium to another is known as	Refraction
180	An apparatus for generation of atomic energy is called a	Reactor
181	A machine used for converting mechanical energy into electrical energy is called a	Generator
182	The first Indian woman in space was	Kalpana Chawla
183	The revolver was invented by	Samuel Colt
184	The refrigerator was invented by	J.Perkins

Science Question Answers – Part 4

76. Question: Why is a new quilt warmer than an old one?
Answer: In a new quilt the cotton is not compressed and as such it encloses more air which is bad conductor of heat. Therefore, it does not allow heat to pass.

77. Question: Curved rail tracks or curved roads are banked or raised on one side. Why?
Answer: Because a fast moving train or vehicle leans inwards while taking turn and the banked or raised track provides required centripetal force to enable it to move round the curve.

78. Question: How do bats fly in dark?
Answer: When bats fly they produce ultrasonic sound waves which are reflected back to them from the obstacles in their way and hence they can fly without difficulty.

79. Question: Water pipes often burst at hill stations on cold frosty nights. Why?
Answer: The temperature may fall below 00C during cold frosty nights which converts the water inside the pipes into ice, resulting in an increase in volume. This exerts great force on the pipes and as a result, they burst.

80. Question: Why are white clothes more comfortable in summer than dark or black ones?
Answer: White clothes are good reflectors and bad absorbers of heat, whereas dark or black clothes are good absorbers of heat. Therefore, white clothes are more comfortable because they do not absorb heat from the sun rays.

81. Question: Why does a rose appear red grass green in daylight?
Answer: Rose absorbs all the constituent colors of white light except red which is reflected to us. Similarly, grass absorbs all colors except green which is reflected t us.

82. Question: Why does a ship rise as it enters the sea from a river?
Answer: The density of sea water is high due to impurities and salts compared to river water as a result; the upthurst produced by the sea water on the ship is more than that of river water.

83. Question: Why are fuse provided in electric installations?
Answer: A safety fuse is made of a wire of metal having a very low melting point. When excess current flows in, the wire gets heated, melts and breaks the circuit. By breaking the circuit it saves electric equipment or installations from damage by excessive flow of current.

84. Question: Why is it easier to lift a heavy object under water than in air?
Answer: Because when a body is immersed in water, it experiences an upward thrust (Archimedes? Principle) and loses weight equal to the weight of the water displaced by its immersed potion, and hence, is easier to lift objects.

85. Question: If a highly pumped up bicycle tyre is left in the hot sunlight, it bursts. Why?
Answer: The air inside the tube increases in volume when heated up. As sufficient space for the expansion of the air is not available because the tube is already highly pumped, it may result in bursting of the tyre.

86. Question: What will be the color of green in blue light?
Answer: Grass will appear dark in color because it absorbs all other colors of the light except its own green color. The blue light falling on grass will be absorbed by it, and hence, it will appear dark in color.

87. Question: Why do two eyes give better vision than one?
Answer: Because two eyes do not form exactly similar images and he fusion of these two dissimilar images in the brain gives three dimensions of the stereoscopic vision.

Science Question Answers – Part 3

51. Question: Why is it less difficult to cook rice or potatoes at higher altitudes?
Answer: Atmospheric pressure at higher altitudes is low and boils water below 100⁰C. The boiling point of water is directly proportional to the pressure on its surface.

52. Question: Why is it difficult to breathe at higher altitudes?
Answer: Because of low air pressure at higher altitudes the quantity of air is less, and so that of oxygen.

53. Question: Why are winter nights and summer nights warmer during cloudy weather than when the sky is clear?
Answer: Clouds being bad conductors of heat do not permit radiation of heat from land to escape into the sky. As this heat remains in the atmosphere, the cloudy nights are warmer.

54. Question: Why is a metal tyre heated before it is fixed on wooden wheels?
Answer: On heating, the metal tyre expands by which its circumference also increases. This makes fixing the wheel easier and therefore cooling down shrinks it; thus fixing the tyre tightly.

55. Question: Why is it easier to swim in the sea than in a river?
Answer: The density of sea water is higher; hence the up thrust is more than that of river water.

56. Question: Who will possibly learn swimming faster-a fat person or a thin person?
Answer: The fat person displaces more water which will help him float much more freely compared to a thin person.

57. Question: Why is a flash of lightening seen before thunder?
Answer: Because light travels faster than sound, it reaches the earth before the sound of thunder.

58. Question: Why cannot a petrol fire be extinguished by water?
Answer: Water, which is heavier than petrol, slips down permitting the petrol to rise to the surface and continue to burn. Besides, the existing temperature is so high that the water poured on the fire evaporates even before it can extinguish the fire. The latter is true if a small quantity of water is poured.

59. Question: Why does water remain cold in an earthen pot?
Answer: There are pores in an earthen pot which allow water to percolate to the outer surface. Here evaporation of water takes place thereby producing a cooling effect.

60. Question: Why do we place a wet cloth on the forehead of a patient suffering from high temperature?
Answer: Because of body?s temperature, water evaporating from the wet cloth produces a cooling effect and brings the temperature down.

61. Question: When a needle is placed on a small piece of blotting paper which is place on the surface of clean water, the blotting paper sinks after a few minutes but the needle floats. However, in a soap solution the needle sinks. Why?
Answer: The surface tension of clean water being higher than that of a soap solution, it cans support the weight of a needle due to its surface tension. By addition of soap, the surface tension of water reduces, thereby resulting in the sinking of the needle.

62. Question: To prevent multiplication of mosquitoes, it is recommended to sprinkle oil in the ponds with stagnant water. Why?
Answer: Mosquitoes breed in stagnant water. The larvae of mosquitoes keep floating on the surface of water due to surface tension. However, when oil is sprinkled, the surface tension is lowered resulting in drowning and death of the larvae.

63. Question: Why does oil rise on a cloth tape of an oil lamp?
Answer: The pores in the cloth tape suck oil due to the capillary action of oil.

64. Question: Why are ventilators in a room always made near the roof?
Answer: The hot air being lighter in weight tends to rise above and escape from the ventilators at the top. This allows the cool air to come in the room to take its place.

65. Question: How does ink get filled in a fountain pen?
Answer: When the rubber tube of a fountain pen immersed in ink is pressed, the air inside the tube comes out and when the pressure is released the ink rushes in to fill the air space in the tube.

66. Question: Why are air coolers less effective during the rainy season?
Answer: During the rainy reason, the atmosphere air is saturated with moisture. Therefore, the process of evaporation of water from the moist pads of the cooler slows down thereby not cooling the air blown out from the cooler.

67. Question: Why does grass gather more dew in nights than metallic objects such as stones?
Answer: Grass being a good radiator enables water vapour in the air to condense on it. Moreover, grass gives out water constantly (transpiration) which appears in the form of dew because the air near grass is saturated with water vapour and slows evaporation. Dew is formed on objects which are good radiations and bad conductors.

68. Question: If a lighted paper is introduced in a jar of carbon dioxide, its flame extinguishes. Why?
Answer: Because carbon dioxide does not help in burning. For burning, oxygen is required.

69. Question: Why does the mass of an iron increase on rusting?
Answer: Because rust is hydrated ferric oxide which adds to the mass of the iron rod. The process of rusting involves addition of hydrogen and oxygen elements to iron.

70. Question: Why does milk curdle?
Answer: Lactose (milk sugar) content of milk undergoes fermentation and changes into lactic acid which on reacting with milk protein (casein) form curd.

71. Question: Why does hard water not lather soap profusely?
Answer: Hard water contains sulphates and chlorides of magnesium and calcium which forms an insoluble compound with soap. Therefore, soap does not lather with hard water.

72. Question: Why is it dangerous to have charcoal fire burning in a closed room?
Answer: When charcoal burns it produces carbon monoxide which is suffocating and can cause death.

73. Question: Why is it dangerous to sleep under trees at night?
Answer: Plants respire at night and give out carbon dioxide which reduces the oxygen content of air required for breathing.

74. Question: Why does ENO’s salt effervesce on addition of water?
Answer: It contains tartaric acid and sodium bicarbonate. On adding water, carbon dioxide is produced which when released into water causes effervescence.

75. Question: Why does milk turn sour?
Answer: The microbes react with milk and grow. They turn lactose into lactic acid which is sour in taste.

Science Question Answers – Part 2

26. Question: Why does a thermometer kept in boiling water show no change in reading after 100⁰C?
Answer: The boiling point of water is 100⁰C. Once water starts boiling at this temperature, thermometer records no change in temperature. The quantity of heat supplied is being utilized as latent heat of evaporation to convert the water at boiling point into vapour.

27. Question: Why do we bring our hands close to the mouth while shouting across to someone far away?
Answer: By keeping hands close to mouth the sound is not allowed to spread (Phenomenon of diffraction of sound) in all direction, but is directed to a particular direction and becomes louder.

28. Question: Why does a corked bottle filled with water burst if left out on a frosty night?
Answer: Because of low temperature the water inside the bottle freezes. On freezing it expands, thereby its volume increases and pressure is exerted on the walls.

29. Question: Why is a small gap left at the joint between two rails?
Answer: To permit expansion of rails due to heat generated by friction of a moving train.

30. Question: Why cannot a copper wire be used to make elements in electric heater?
Answer: Copper melts at 108.3⁰C and forms a black powder on reacting with atmospheric oxygen. For heater elements a metal should have more resistance to produce heat.

31. Question: Why are water or mercury droplets always round when dropped on a clean glass?
Answer: The surface of a liquid is the seat of a special force as a result of which molecules on the surface are bound together to form something like a stretched membrane. They tend to compress the molecules below to the smallest possible volume, which causes the drop to take a round shape as for a given mass he sphere has minimum volume.

32. Question: Why does a balloon filled with hydrogen rise in the air?
Answer: Weight of hydrogen is less than the weight of air displaced by it. In balloons hydrogen is normally filled because it is lighter than air.

33. Question: Why do we lean forward while climbing a hill?
Answer: In order to keeps the vertical line passing through our centre of gravity always between our feet, which is essential to attain equilibrium or stability.

34. Question: Why does smoke curl up in the air?
Answer: Smoke contains hot gases which being lighter in weight, follows a curved path because of the eddy currents that are set up in the air.

35. Question: Why does an electric bulb explode when it is broken?
Answer: The bulb encompasses partial vacuum and as it breaks, air rushes in causing a small explosion.

36. Question: Why does a man fall forward when he jumps out of a running train or bus?
Answer: He is in motion while in the train or bus. When he jumps out, his feet comes to rest while touching the ground but his upper portion which is still in motion propels him forward.

37. Question: Why does an ordinary glass tumbler crack when very hot tea or milk is poured in it?
Answer: When a hot liquid is poured into a tumbler, the inner layer of the tumbler gets heated, it expands before the outer layer and an unequal expansion of both layers causes the tumbler to crack.

38. Question: Why is a compass used as an indicator of direction?

Answer: The magnetic needles of a compass under the influence f the earth?s magnetic field lie in a north-south direction. Hence, we can identify direction.

39. Question: Why is water from a hand pump warm in winter and cold in summer?
Answer: In winter, the outside temperature is lower than that of water flowing out of the pump, and therefore, the water is warm. Whereas in summer, the outside temperature is higher than the water of the pump, and therefore, it feels cold.

41. Question: Why is a rainbow seen after a shower?
Answer: After a shower, the clouds containing water droplets act like a prism through which the white light is dispersed producing a spectrum.

42. Question: Why does a swimming pool appear less deep than is actually is?
Answer: The rays of light coming from the bottom of the pool pass from a denser medium (water) to a rarer medium (air) and are refracted (bend away from the normal). When the rays return to the surface, they form an image of the bottom of the pool at a point, which is little above the real position.

43. Question: Why is one?s breath visible in winter but not in summer?
Answer: In winter, water vapor contained in the breath condenses into small droplets, which become visible but in summer they are quickly evaporated and not seen.

44. Question: Why doesn?t the electric filament in an electric bulb burn up?
Answer: Firstly, because is made of tungsten which has a very high melting point (3410⁰C) whereas the temperature of the filament required to glow is only 2700oC. Secondly, oxygen is absent since the bulb is filled with an inert gas which does not help in burning.

45. Question: Why does blotting paper absorb ink?
Answer: Blotting paperhas fine pores, which act like capillaries. When a portion of blotting paper is brought in contact with ink, ink enters the pores due to surface tension (capillary action f liquids) and is absorbed.

46. Question: Why does a small iron sink in water but a large ship float?
Answer: The weight of water displaced by an iron ball is less than its own weight, whereas water displaced by the immersed portion of a ship is equal to its weight (Archimedes? Principle).

47. Question: Why does ice float on water?
Answer: The weight of the ice block is equal to the weight of the liquid displaced by the immersed portion of the ice.

48. Question: Why does moisture gather outside a tumbler containing cold water?
Answer: The water vapour in the air condenses on cooling and appears as droplets of water.

49. Question: Why does kerosene float on water?
Answer: Because the density of kerosene is less than that of water. For the same reason cream rises in milk and floats at the top.

50. Question: Why is the water in an open pond cool even on a hot summer day?
Answer: As the water evaporates from the open surface of a pond, heat is taken away in the process, leaving the surface cool.

Science Questions Answers – Part 1

1. Question: A man with a load jumps from a high building. What will be the load experienced by him?
Answer: Zero, because while falling, both the man and the load are falling at the same acceleration i.e. acceleration due to gravity.

2. Question: A piece of chalk when immersed in water emits bubbles. Why?
Answer: 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.

3. Question: Why does a liquid remain hot or cold for a long time inside a thermos flask?
Answer: The presence of air, a poor conductor of heat, between the double glass wall of a thermos flask, keeps the liquid hot or cold inside a flask for a long time.

4. Question: Why does a ball bounce upon falling?
Answer: When a ball falls, it is temporarily deformed. Because of elasticity, the ball tends to regain its original shape for which it presses the ground and bounces up (Newton’s Third Law of Motion).

5 Question: Why is standing in boats or double decker buses not allowed, particularly in the upper deck of buses?
Answer: On tilting the centre of gravity of the boat or bus is lowered and it is likely to overturn.

6. Question: Why is it recommended to add salt to water while boiling dal?
Answer: By addition of salt, the boiled point of water gets raised which helps in cooking the dal sooner.

7. Question: Why is it the boiling point of sea water more than that of pure water?
Answer: Sea water contains salt, and other impurities which cause an elevation in its boiling point.

8. Question: Why is it easier to spray water to which soap is added?
Answer: Addition of soap decreases the surface tension of water. The energy for spraying is directly proportional to surface tension.

9. Question: Which is more elastic, rubber or steel?
Answer: Steel is more elastic for the same stress produced compared with rubber.

10. Question: Why is the sky blue?
Answer: Violet and blue light have short waves which are scattered more than red light waves. While red light goes almost straight through the atmosphere, blue and violet light are scattered by particles in the atmosphere. Thus, we see a blue sky.

11. Question: Why Does ink leak out of partially filled pen when taken to a higher altitude?
Answer: As we go up, the pressure and density of air goes on decreasing. A 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 the air outside.

12. Question: On the moon, will the weight of a man be less or more than his weight on the earth?

Answer: The gravity of the moon is one-sixth that of the earth; hence the weight of a person on the surface of the moon will be one-sixth of his actual weight on earth.

13. Question: Why do some liquid burn while others do not?
Answer: A liquid burns if its molecules can combine with oxygen in the air with the production of heat. Hence, oil burns but water does not.

14. Question: Why can we see ourselves in a mirror?
Answer: We see objects when light rays from them reach our eyes. As mirrors have a shiny surface, the light rays are reflected back to us and enter our eyes.

15. Question: Why does a solid chunk of iron sink in water but float in mercury?
Answer: Because the density of iron is more than that of water bus less than that of mercury.

16. Question: Why is cooking quicker in a pressure cooker?
Answer: As the pressure inside the cooker increases, the boiling point of water is raised, hence, the cooking process is quicker.

17. Question: When wood burns it crackles. Explain?
Answer: Wood contains a complex mixture of gases and tar forming vapors trapped under its surface. These gases and tar vapors escape, making a cracking sound.

18. Question: Why do stars twinkle?
Answer: The light from a star reaches us after refraction as it passes through various layers of air. When the light passes through the earth?s atmosphere, it is made to flicker by the hot and cold ripples of air and it appears as if the stars are twinkling.

19. Question: Why is it easier to roll a barrel than to pull it?
Answer: Because the rolling force of friction is less than the dynamic force of sliding friction.

20. Question: If a feather, a wooden ball and a steel ball fall simultaneously in a vacuum, which one of these would fall faster?
Answer: All will fall at the same speed in vacuum because there will be no air resistance and the 
earth?s gravity will exert a similar gravitational pull on all.

21. Question: When a man fires a gun, he is pushed back slightly. Why?
Answer: As the bullet leaves the nozzle of the gun?s barrel with momentum in a forward direction, as per Newton’s Third Law of Motion, the ejection imparts to the gun as equal momentum in a backward direction.

22. Question: Ice wrapped in a blanket or saw dust does not melt quickly. Why?
Answer: Both wood and wool are bad conductors of heat. They do not permit heat rays to reach the ice easily.

23. Question: Why do we perspire on a hot day?
Answer: When the body temperature rises, the sweat glands are stimulated to secrete perspiration. It is nature’s way to keep the body cool. During the process of evaporation of sweat, body heat is taken away, thus giving a sense of coolness.

24. Question: Why does ice float on water but sink in alcohol?
Answer: Because ice is lighter than water it floats on it. However, ice is heavier than alcohol and therefore it sinks in alcohol.

25. Question: Why do we perspire before rains?
Answer: Before the rain falls, the atmosphere gets saturated with water vapors; as a result, the process of evaporation of sweat is delayed.

List of Different Types of Doctors and What They Do

There are different types of doctors and what they do depends on their field of specialty. If you are a budding doctor and want to know more about the career options related to types of doctors and what they do, then the following article will prove to be a useful read…

Doctor, a profession that elicits respect and high esteem from people from all walks of life. The profession of saving lives, helping new life come into the world and giving new hope to the ill and distraught, is considered to be next to godliness. There are different types of doctors and what they do is to help make life better. All of us have at least once in our lives visited a doctor and the doctor has helped us in some way or the other. Many aspire to become a doctor to help the sick get rid of their maladies. Medicine is one of the most sought after professions in the world and is one of the highest paying jobs in the world. Wouldn’t it feel wonderful to go home with the feeling of satisfaction that you just helped saved a life? If you too are medically inclined and wish to do your bit for society and also have a stable financial future, then becoming a doctor is the way to go! The following list of different types of doctors and what they do will help you learn more about this highly noble medical job.

Different Types of Doctors and What They Do

The world is Mother Nature’s marvel that is blessed with different wonders of the natural world like the human body system. But, with every blessing comes some kind of curse and this curse that plagues the living world is diseases. There are different kinds of diseases and disorders that are either due to microorganisms, parasites, non-functioning of different organs in the body, biochemical imbalances, genetic or hereditary problems, etc. Many times, people suffer from different kinds of accidents natural and man-made, gunshots, stabbing wounds, burns, and many other innovative types of grievous injuries. These different medical problems are taken care of by different types of doctors and what they do, according to their field of specialization. There are hundreds of examples around the world, where doctors have been able to pull men out of the jaws of death with their medical expertise. If you too want to face different medical challenges, then the following list of different types of doctors and what they do, will help you find a foothold in the medical world.

Audiologists: These doctors help patients with different ear problems and help children who are either deaf or mute to learn to communicate.

Allergist: These doctors help in treating different kinds of allergies and immune system disorders like hay fever, asthma, etc.

Andrologists: The andrologist helps in diagnosing and treating disorders related to the male reproductive system.

Anesthesiologists: They study and administer anesthesia and anesthetic medicines that help in facilitating treatment, diagnosis of medical conditions and complete minor and major surgeries without the patient having to feel more than the prick of the anesthetic needle.

Cardiologist: These are doctors of the heart that diagnose and treat heart diseases and cardiovascular diseases.

Dentist: Perhaps one of the most feared doctors of all is the dentist due to their tooth extraction habits! These doctors are concerned with dental health, teeth and dental problems like cavities and bleeding gums. They treat gum diseases, straighten teeth, carry out root canals, etc.

Dermatologists: A dermatologist studies the skin, its structure, functions, and diseases, as well as its appendages (nails, hair, sweat glands) and treats the related ailments.

Endocrinologists: A doctor who studies disorders of the endocrine system and their glands, like thyroid problems and other such hormonal imbalances and the specific secretions of hormones is what entails an endocrinologist job description.

Epidemiologists: Epidemiologist are the doctors who are also known as ‘disease detectives’. They carry out study of diseases and come up with ways of prevention of diseases through vaccinations, etc.

Family Practician: These are your friendly neighborhood doctors who are basically general physicians, and treat patients of all ages & medical non-emergency conditions usually in a clinic.

Gastroenterologists: A doctor that studies diseases of digestive system and gives treatment related to the gasteroenterlogy.

Gynecologists: The doctor who studies and treats diseases of the female reproductive system.

Hematologists: A hematologist studies blood and its diseases.

Hepatologists: Hepatologists study and treat diseases of the liver.

Immunologists: The doctor who studies all aspects of the immune system in all organisms and gives treatment to diseases of the immune system.

Infectious Disease Specialists: The doctors who study & treat diseases that are caused by viruses, bacteria, fungi, parasites, and are usually based within the hospital. These doctors are involved in a lot of research work.

Internal Medicine Specialists: These doctors provide diagnosis, management and nonsurgical treatment of unusual or serious diseases and are usually found working in hospitals as intensivists.

Internists: These doctors focus on adult medicine and have completed a special study related to the prevention and treatment of adult diseases.

Medical Geneticist: A medical geneticist is the doctor that carries out studies, tests, treatments and counseling patients with genetic diseases.

Microbiologists: A microbiologist studies causes, diagnosis and treatment of infectious diseases.

Neonatologist: The neonatologist is the doctor that provides medical care to premature and critically ill newborn babies.

Nephrologist: The doctor who treats kidney diseases and problems.

Neurologist: These are doctors who treat one of the most delicate and important organs of the body, the brain. They treat conditions like seizures, strokes, Parkinson’s, Alzheimer’s, etc.

Neurosurgeons: These are surgeons who treat central and peripheral nervous system diseases that can be cured or controlled to some extent with mechanical intervention.

Obstetrician: This is a part of gynecology and the doctors are experts with childbirth, C-sections, gynecological surgeries like hysterectomy, surgical removal of ovarian tumors, examination of the pelvic region, PAP smears, prenatal care, etc.

Oncologist: An oncologist job description entails treating cancer patients.

Ophthalmologist: The doctor that takes care of eyes and treats various eye problems and performs different eye surgeries.

Orthopedic Surgeons: The doctor who is concerned with the skeletal system of the human body, that is, bones. These doctors make no bones about broken, fractured or arthritis struck bones!

ENT specialists: An ENT specialist treats the Ear, the Nose and the Throat, as well as to some extent some ailments of the head and the neck. This field is also known as otolaryngology.

Perinatologist: The doctor who is an expert in caring and treating high risk pregnancies.

Paleopathologist: These doctors are into the study of ancient diseases.

Parasitologist: The study of parasites, their biology and pathology, as well as the parasitic diseases caused by them is carried out by a parasitologist.

Pathologists: The study of abnormalities in living organisms, diagnosing diseases and conditions from tissue samples like blood or biopsy samples. They also work as medical examiners & carry out autopsies to determine the cause of death. These doctors usually do not come in contact with the patients directly as their work is mostly lab work. They are therefore called as a ‘doctor’s doctor’ as they speak to doctors of the patients rather than the patient himself. There are many doctors who specialize in forensic pathology and help the police and FBI solve crimes.

Pediatricians: A pediatrician is the doctor who studies and treats medical problems of infants, children, and adolescents.

Physiologists: A physiologist is a life science doctor who specializes in physiology.

Physiatrist: The doctor whose specialty is medicine and rehabilitation.

Plastic Surgeon: A plastic surgeon is the doctor who can literally change the life and look of a patient. He performs cosmetic surgery to repair skin and structural problems that may alter the personality of the patient for good.

Podiatrists: The doctor who studies and treats disorders of the foot and ankle.

Psychiatrists: These doctors specialize in psychiatry, that is, a branch of medicine concerned with the study, diagnoses and treatment of mental illness and behavioral disorders.

Pulmonologist: The doctor who diagnoses and treats lung conditions and treatments and even manages critical care patients admitted in the ICU and those that are on ventilator support.

Radiologists: The study of medical use of X-rays or other imaging technologies for diagnoses and treatment of disease is carried out by an radiologist.

Rheumatologsists: These doctors treat allergic conditions & autoimmune disorders.

Surgeons: A surgeon performs operations, related to different sub-specialties of medicine like general surgery, neurosurgery, cardiovascular, cardiothoracic surgery, ENT, maxillo-facial surgery, plastic surgery, oral surgery, transplant surgery, urology, etc.

Urologists: The urologist is a doctor who studies the urinary system and treats urinary tract infections.

Emergency Doctors: Emergency doctors are those who offer their services in the emergency room (ER) and are on call 24/7. They treat various emergency cases that vary from poisoning, broken bones, burns, heart attack, and anything and everything that can be termed as a medical emergency.

Veterinarian: Although, all the above fields are concerned with human treatment, the veterinarian is also a type of doctor and what they do is treat animals. They take care of different diseases of the animal world. There are different kinds of doctors within the field of animal medicine and like human doctors, the veterinarian too has his field of expertise in case of animal problems.

This was some medical career information related to different types of doctors and what they do. There are over 50 to 60 specialties of medicine and each specialty with different types of doctors and their salaries. You need to understand your area of interest and then choose your line of specialty as a career. I hope this article on different types of doctors and what they do has helped you find your field of interest.

DISCOVERY / INVENTION IN MEDICAL SCIENCE

SNo	Discovery / Invention	Year	Discoverer / Inventor	Country
1	Adrenaline	1894	Schafer and Oliver	Britain
2	Anesthesia, Local	1885	Koller	Austria
3	Anesthesia, Spinal	1898	Bier	Germany
4	Anti-toxins (Science of Immunity)	1890	Behring and Kitasato	Germany, Japan
5	Aspirin	1889	Dreser	Germany
6	Ayurveda	2000-1000 BC		India
7	Bacteria	1683	Leeuwenhock	Netherlands
8	Bacteriology	1872	Ferdinand Cohn	Germany
9	Biochemistry	1648	Jan Baptista Van Helmont	Belgium
10	Blood Plasma storage (Blood bank)	1940	Drew	U.S.A
11	Blood Transfusion	1625	Jean-Baptiste Denys	France
12	Cardiac Pacemaker	1932	A.S Hyman	U.S.A
13	CAT Scanner	1968	Godfrey Hounsfield	Britain
14	Chemotherapy	1493-1541	Paracelsus	Switzerland
15	Chloroform as anaesthetic	1847	James Simpson	Britain
16	Chloromycetin	1947	Burkholder	U.S.A
17	Cholera T.B germs	1877	Robert Koch	Germany
18	Circulation of blood	1628	William Harvey	Britain
19	Cryo-Surgery	1953	Henry Swan	U.S.A
20	Diphtheria germs	1883-84	Klebs and Loffler	Germany
21	Electro-Cardiograph	1903	Willem Einthoven	Netherlands
22	Electro-encephalogram	1929	Hand Berger	Germany
23	Embryology	1792-1896	Kari Ernest Van Baer	Estonia
24	Endocrinology	1902	Bayliss and Starling	Britain
25	First Test Tube Baby	1978	Steptoe and Edwards	Britain
26	Gene Therapy on humans	1980	Martin Clive	U.S.A
27	Genes associated with cancer	1982	Robert Weinberg and others	U.S.A
28	Heart Transplant Surgery	1967	Christian Barnard	S. Africa
29	Histology	1771-1802	Marie Bichat	France
30	Hypodermic syringe	1853	Alexander wood	Britain
31	Kidney Machine	1944	Kolf	Netherlands
32	Leprosy Bacillus	1873	Hansen	Norway
33	LSD (Lysergic acid diethylamide)	1943	Hoffman	Switzerland
34	Malaria Germs	1880	Laveran	France
35	Morphine	1805	Friderich Sertumer	Germany
36	Neurology	1758-1828	Franz Joseph Gall	Germany
37	Nuclear magnetic resonance imaging	1971	Raymond Damadian	U.S.A
38	Open Heart Surgery	1953	Walton Lillehel	U.S.A
39	Oral Contraceptive Pills	1955	Gregory Pincus, Rock	U.S.A
40	Penicillin	1928	Alexander Fleming	Britain
41	Physiology	1757-66	Albrecht Von Haller	Switzerland
42	Positron emission Tomography	1978	Louis Sokoloff	U.S.A
43	Rabies Vaccine	1860	Louis Pasteur	France
44	Recombinant-DNA technology	1972-73	Paul Berg, H.W. Boyer,S Cohen	U.S.A
45	Reserpine	1949	Jal Vakil	India
46	Rh-factor	1940	Karl Landsteiner	U.S.A
47	Serology	1884-1915	Paul Ehrlich	Germany
48	Sex hormones	1910	Eugen Steinach	Australia
49	Small Pox eradicated	1980	W.H.O Declaration	UN
50	Stethoscope	1819	Rene Laennec	France
51	Streptomycin	1944	Selman Waksmann	U.S.A
52	Synthetic Antigens	1917	Landsteiner	U.S.A
53	Terramycin	1950	Finlay and Others	U.S.A
54	Thyroxin	1919	Edward Calvin-Kendall	U.S.A
55	Typhus Vaccine	1909	J. Nicolle	France
56	Vaccination	1796	Edward Jenner	Britain
57	Vaccine, Measles	1963	Enders	U.S.A
58	Vaccine, Meningitis	1987	Gardon, et al. Connaught Lab	U.S.A
59	Vaccine, Polio	1954	Jonas Salk	U.S.A
60	Vaccine, Polio-orai	1960	Albert Sabin	U.S.A
61	Vaccine, Rabies	1885	Louis Pasteur	France
62	Vaccine, Smallpox	1776	Jenner	Britain
63	Virology	1892	Ivanovski and Bajernick	USSR, Netherlands
64	Vitamin A	1913	Mc Collum and M. Davis	U.S.A
65	Vitamin B1	1936	Minot and Murphy	U.S.A
66	Vitamin C	1919	Froelich Holst	Norway
67	Vitamin D	1925	Mc Collum	U.S.A
68	Vitamin K	1938	Doisy Dam	U.S.A
69	Western Scientific Therapy	460-370 BC	Hippocrates	Greece
70	Yoga	200-100 BC	Patanjali	India