General Science Gk 8
General Knowledge : General Science Gk 8
| Who is usually considered to be the discoverer of oxygen? | Joseph Priestley. |
| Who made the first balloon that could fly? | Joseph & Jacques Montgolfier. |
| Who made the first electric motor? | Michael Faraday. |
| Who made the first locomotive that had successful runs? | George Stephenson. |
| Who made the first printing press with moveable types? | Johannes Gutenberg of Germany in the middle of the | 15* century. |
| Who made trains run by steam engine popular? | George Stephenson |
| Who pioneered the use of antiseptic? | Joseph Lister. |
| Who produced the first synthetic dye? | William Perkin. |
| Who produced the world's first petrol driven car? | KarlBenz. |
| Who proposed the Centigrade Scale? | Anders Celsius first proposed the centigrade thermometer, which has a scale of 100 degrees separating the boiling and freezing points of water. |
| Who propounded the theory of relativity? | Albert Einstein. |
| Who propounded the theory of relativity? | Albert Einstein |
| Who propounded the theory that the sun and not the earth is the centre of the Solar System? | Nicolus Copernicus (Bhaskaracharya of lllh Century A.D and Aryabhata of the fifth century A.D seem to be aware of this). |
| Who was Pythagoras? | He was a Greek Philosopher and mathematician who lived around 520 BC. |
| Who was the first man on the moon? | Neil Armstrong. |
| Who was the first man to make a phonograph (gramophone)? | Thomas Alva Edison. |
| Who was the first man to point out that things get spoiled because of germs? | Loius Pasteur. |
| Who was the first man to study sunspots? | A German by name Hienrich Schwabe. |
| Who was the first man to travel in space? | Yuri Gagarin. |
| Who was the first person to find out that microscopic organisms are responsible for milk, wine, etc turning sour? | Louis Pasteur. |
| Who was the first person to show that the Milky Way is composed of stars? | Galileo Galilei. |
| Who was the first woman of Indian origin to travel in a space vehicle? | Kalpana Chawla. |
| Who was the first woman to travel in space? | Valentina Tereshkova. |
| Who was the founder of the system of medicine known as Homoeopathy? | Samuel Hahnemann. |
| Who was the person to first identify the proton? | Ernest Rutherford. |
| Who was the scientist who initiated the Atomic Energy Programme of India? | Homi Bhabha. |
| Who wrote the book on "The Origin of species by means of Natural Selection"? | Charles Darwin. |
| Whose notebooks were Filled with ideas and sketches of inventions, including designs for an airplane? | Leonardo da Vinci. |
| Why are droplets formed on the outer surface of a glass when cold water is poured into it? | The moisture in the air condenses on the cool outer surface of the glass. |
| Why are oceans important to man? | They enable man to travel to distant corners of the world. They also provide food, oil and minerals. |
| Why are tea plants cut when they grow to a height of two metres or more? | To force more tender leaves to branch out and make handpicking of leaves easier. |
| Why are the blades of the fan slightly curved? | If you wish to carry sand or any solid substance from one place to another, you can carry little if there are straight metal strips. A pail can carry much more. In the case of air, which is a fluid, a slightly curved blade is enough to help circulate air in the room. |
| Why are whales hunted? | For the blubber or the oil in them. |
| Why can't a horse sit? | They don't have knees on their hind legs. |
| Why can't cranes perch on trees branches? | They cannot curl their toes. As a result they cannot have a firm grip on a branch. |
| Why did Dr. Lister use carbolic acid to cover wounds? | To prevent infection. |
| Why did Galileo come into conflict with the church? | Because he supported the Copernican theory that the planets (including the earth) revolve around the sun. |
| Why didn't the British plant rubber in England? | Rubber grows only in tropical countries. |
| Why do animals like rats and squirrels keep gnawing at things? | Gnawing helps wear down their teeth. If they did not gnaw at things their teeth would keep on growing. |
| Why do crocodiles shed tears? | They secrete the excess salt in die body through this action. They get rid of this by means of a gland near the comer of the eyes. |
| Why do dogs pant? | To keep themselves cool. When they throw out the tongue while panting, the moisture in the tongue evaporates. This directly results in cooling. Humans keep themselves cool by sweating and then evaporation of the sweat, from a large surface of the skin. |
| Why do earth and other planets revolve around the sun? | Sun's gravitational force keeps the planets in a fixed orbit. |
| Why do flocks of swans fly in a V-formation? | By flying in this way they meet minimum resistance from the air to their flying. |
| Why do people cover ice slabs with sawdust? | Sawdust is a bad conductor of heat and slows down the melting of ice. |
| Why do people living in the deserts prefer white colour for their robes? | White coloured robes do not absorb light, whereas dark-coloured clothes absorb the light and conduct heat to the body. |
| Why do planes flying at great speeds leave white fumes behind? | The planes leaving fume behind are jet planes. In a basic jet engine air is compressed and forced into a chamber, where fuel is added. Here combustion (burning) takes place. The hot gases that are produced escape from the base of the engine. This pushes the aircraft forward. The white fumes that you see are the hot gases as they escape out. Since the temperature around the jet is low, the fume condenses and becomes visible. |
| Why do snakes shed their skin? | Unlike human beings, whose growth stops around 20 years, snakes keep on growing. This becomes possible because they keep casting off old skin and develop new skin, when the old one is shed. |
| Why do some people have fat legs? | The cause of filaria (elephant leg) are worms called Wuchereia bancrofti the female worm gives birth to young worms and not eggs. These young ones, called microfilaria, find the way into blood stream of their victims and from there into the lymphatic vessels. The immediate cause of filarial is a mosquito called culex. |
| Why do tigers turn into man-eaters? | When tigers become old or are incapacitated because of injury, they prey on human beings. A tiger that has preyed on man and has tasted human flesh often continues to prey on man. |
| Why do water pipes burst in hill stations? | There is an unusual expansion of water, when its temperature goes below 4° C. Instead of contracting, the water begins to expand till ice is formed at zero degrees Celsius. Unable to bear the pressure, the pipe bursts. |
| Why do we feel hungrier in winter? | In winter we need energy to maintain the body temperature in addition to sustaining normal activities of the body. To meet this requirement of energy we eat more. |
| Why do we feel sleepy after a heavy meal? | The blood circulation to the digestive tract increases. As a result the blood circulation to the brain is reduced. This makes us sleepy. |
| Why do we see lightning much before we hear thunder? | This is because light travels much faster than sound. Light travels @ 2.99 x 108 mt / sec (2,99,000 km/sec) whereas sound travels @ 333 mt/sec. |
| Why does a fire look yellowish, at times? | When the combustion (burning) is not complete the colour of fire becomes yellowish. When the combustion is complete, the colour changes to pale blue. |
| Why does a jet of water come out of a whale's back? | It is air, exhaled by the whale. |
| Why does a metal rod feel cooler than a piece of wood? | Metals are good conductors of heat. When we touch a metallic rod, it takes away the heat from the hand and feels cooler. A piece of wood is a bad conductor of heat and therefore it does not take away the heat from our hands. |
| Why does a rhinoceros spend so much time in mud? | To keep cool and protect itself from insect bites. |
| Why does a snake flick its tongue so often? | To smell the surroundings. |
| Why does an apple that has been cut open turn brown and then black? | Polypnenols in the apple get oxidised. |
| Why does cutting onions give a burning sensation in the eyes? | When onions are cut, volatile oils, containing sulphur, are released. In combination with the water in the eye, they produce irritation. |
| Why does it take longer to cook food at high altitudes? | The atmospheric pressure at high altitudes is much lower than at sea level. The greater the pressure, the faster the cooking. |
| Why does milk spill out when boiled? | When milk is heated, the water in it starts evaporating. The fat globules present in the milk get separated and float on the top as cream. On further heating, more water vapour is formed. But when it tries to escape, it gets trapped by the thick layer of cream on the top. The water vapour pushes up the layer of cream and forms a bulge, which finally bursts out, causing the spill. |
| Why does not the moon have an atmosphere? | Even if it had some atmosphere, its mass is so low that gravity on the surface is not enough to retain the atmosphere. |
| Why does the liquid in the egg become solid when heated or boiled? | Due to congealing - coagulation of the yolk. |
| Why does the ostrich eat sand or gravel? | To digest its food. |
| Why does the planet Mars appear red? | Due to the highly oxidised surface of the planet. |
| Why does the running sound of a train change when it passes over a bridge? | Sound travels in the form of waves. The frequency of the waves and die amplitude (the width) of the waves determine the sound. The sound waves are of different kinds, when a train moves on solid ground, and when it moves on a bridge, whether made of steel or plain concrete. |
| Why does the sound of water keep changing when a vessel is being filled under a tap? | Sound is produced by the movement of columns of air. Strike a stainless steel glass with a spoon. A sound is produced. Stop the vibration of the steel glass with your fingers. There will be no sound. When water is being filled in a vessel, sound is produced because of the movement of the column of air. This column becomes smaller and smaller as the water level rises in the vessel. Hence the sound changes. |
| Why does water in an earthen pot become very cool in summer? | Earthem pots have tiny holes from which water seaps out to the surface. When this water evaporates, it takes away the latent heat of vaporisation and keeps the pot {and its contents) cool. |
| Why doesn't a crocodile harm the plover birds that enter its mouth? | Because the plover birds enter the mouth of the crocodile and eat tit-bits found there. This helps the crocodiles to improve their oral hygiene. Therefore crocodiles do not harm the plover birds. |
| Why doesn't ice sink in water? | Ice is lighter than water. After the temperature of water cools down to 4° Celsius (instead of contracting) water keeps on expanding till it reaches 0° Celsius and becomes ice. |
| Why is a soap bubble always spherical and not a square or a triangle? | When a soap bubble forms and goes up in the air, it is subject to immense pressure from all sides. Only a spherical shape can withstand maximum pressure. That is why soap bubbles are always spherical. |
| Why is an earthworm also called 'a Fanners best friend'? | The earthworm is called the farmer's friend because it helps him to keep the soil rich and loose so that plants can grow. As they burrow into soft soil, they swallow some of it, which passes through their bodies and finally is left behind as castings. This is enriched material. |
| Why is food preserved in a refrigerator? | Most bacteria are destroyed as the temperature of the surroundings rises. Temperatures higher than 40° C do not favour growth of bacteria. Similarly low temperatures prevent bacteria from multiplying. Hence food is preserved in the refrigerator by keeping its contents at low temperature. |
| Why is helium used in gas balloons? | Because helium is very light and does not burn. |
| Why is it dangerous to look at die sun during an eclipse? | During solar eclipse, the ultraviolet rays are in such high proportion in sunrays, that they can cause irrepairable damage to the eye. |
| Why is it dangerous to walk on quicksand? | Quicksand is a bed of very fine, powdery wet sand. It is a thick fluid. Once a foot is placed on quicksand, it is not easy to pull it away. The foot may slowly sink in the quicksand. Struggling to take out the foot may sink the foot further down. It is advisable to wait for help. If a man remains calm and does not move his foot, he may stop sinking. |
| Why is it that some people have a dark skin? | The dark colour of the skin is due to a pigment called melanin. On exposure to sunlight, man's skin undergoes gradual tanning to protect the skin from injurious solar rays. |
| Why is polished rice less healthy than unpolished rice? | The husk of food grains (rice, wheat, etc) has Vitamins, much of which are lost when the grains are polished. |
| Why is selenium used in the making of photoelectric cells? | Photoelectric cells convert light into electricity. Selenium is used in making diese cells because its electrical conductivity increases when light strikes it and because it can convert light into electricity. |
| Why is the Egyptian plover bird popularly called the "crocodile bird"? | The Egyptian plover bird has been nicknamed the crocodile bird following an account by Herodotus that he saw these birds enter the open jaws of crocodiles and pick pieces of food from their gums. |
| Why is the housefly considered a health hazard? | On their legs they may carry millions of germs. When they rest on a food plate, these may be transferred to the object they rest on. |
| Why is the rainbow seen only during and after the rain? | This is so because the rain drops serve like prisms and diffract the white light of the sun into violet, indigo, blue, green, yellow, orange and red colours. |
| ZETA stands for | Zero Energy Thermonuclear Assembly |
| Zoology is the study of | Animal life |
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