Science-2

Science-2

No. Question Answer 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 185 Which is the only common metal that is liquid at room temperature? Mercury 186 When a fire is caused by an electric short circuit, why must you not throw water? If you throw water on a fire caused due to short circuit, you may be electrocuted because water is a good conductor of electricity. 187 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. 188 Which planet is the closest to the Sun? Mercury 189 Which is the hottest planet? Venus 190 How much time does the earth take to complete a revolution around the sun? 365 % days. 191 Why are whales hunted? For the blubber or the oil in them. 192 Where do platypuses live? In burrows near water. 193 How many days does the moon take to go round the earth? 27 1/3 days. 194 Among the insects that are extant, (that are living still), which is the most ancient? Cockroach. 195 What is meant by fulcrum? Fulcrum is the point about which a bar or lever will rotate, when a force is applied at any distance from that point or axis. 196 What kind of leaves do silkworms thrive on? Mulberry leaves. 197 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. 198 How does a Pitcher Plant eat flies? A Pitcher Plant is hollow and tubular. The surfaces are slippery and they have hairs, which point downwards. When an insect lands on a pitcher plant, it is impossible for it to escape because of the slippery surface and the downward-pointed hairs. It is then easily digested. 199 What is the Indian name for the planet Mercury? Budha. 200 Where in India do the migratory cranes of Siberia settle down? The Rann of Kutch. 201 How many arms does a starfish have? Usually five. 202 What is a solar eclipse? The moon comes in between the sun and the earth, and thereby prevents sunlight from reaching the earth. 203 Who first saw mountains and craters on the moon using a telescope? Galileo Galilei 204 Which is the largest animal on land? African Elephant. 205 Why does a rhinoceros spend so much time in mud? To keep cool and protect itself from insect bites. 206 Which country first used fingerprints to identify people? Assyria and China. 207 In which country was silk first made? China. 208 What is cholesterol? Cholesterol is a fat found in the human body and the body of other large animals. In its pure form it looks like white sugar. It is made up of tiny crystals, which can be seen under a microscope. It is said that too much cholesterol in the blood is responsible for the hardening of arteries and for various other heart ailments. 209 How did the watch get its name? From the fact that you have to watch it to know the time. 210 What is vulcanisation of rubber? The process of hardening rubber by adding sulphur and heating the mixture is vulcanisation. Vulcanisation was discovered by Charles Goodyear. Raw rubber is sticky. It hardens when the temperature is low and softens when it is high. Charles Goodyear discovered that by combining raw rubber with sulphur and by heating it, the rubber becomes stronger and elastic and also resistant to solvents. Today almost all rubber, whether natural or synthetic is vulcanized. 211 When faced with danger what does a Pangolin do? It rolls into a ball. 212 Where is the entrance to a baya's nest? At the bottom of the nest. 213 What is glass made from? Limestone, Silica and Soda ash. 214 What is the microscopic study of plant and animal tissue called? Histology. 215 How does a mariner's compass help the mariner? The needle of the compass always points towards the magnetic north pole. This indicates the direction in which the ship is moving. 216 Which is the second largest planet in our Solar System? Saturn. 217 How many weeks after birth does the young one of a cat opens its eyes? Three weeks. 218 The arms of the Octopus have sucker cups. What is the use of these cups? To hold onto a surface. 219 What food does a bear love most? Honey. 220 How did the Romans rub off what was written on a wooden slate coated with wax? By heating the slate, the wax was melted. The slate became ready to reuse. 221 What are seashells? Outer casings of soft-bodied animals, called molluscs. 222 How is a pearl formed within the body of an oyster? A pearl is formed when a grain of sand or other foreign matter gets between the hard outer shell and the inner coat called the mantle, of a mollusc. The mollusc surrounds the irritation with nacre, a secretion from the mantle. Many thin layers of nacre give the pearl its lustre. 223 How much time does Pluto take to complete a revolution around the sun? 248 years. 224 What is a Catamaran? A boat with twin parallel hulls. [From the Tamil words katta and maram, meaning tied up (katta) tree (maram). 225 How many ears does a spider have? None. 226 How much time does light take to reach the earth from the sun? 8 minutes. 227 What is acceleration? The time rate at which the velocity of a point is changing is acceleration. Velocity is just the speed (miles per hour or kilometres per second). The term acceleration is used when the speed keeps increasing. The term deceleration is used when the speed becomes less and less. 228 How does a spider eat its food? The spider inserts his fangs into the victim's body and uses them as straws to suck out the liquid. 229 Who invented the telescope? Hans Lippershey. 230 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. 231 What is common to dolphins and humans? They are both mammals. 232 In which country was the day first divided into 12 parts? Babylon (modern Iraq). 233 How does a rocket move forward? It moves forward due to propulsion. You must have seen that a boatman pushes the water backwards with his oar. This creates a force in the forward direction. This is propulsion. Newton's third law of motion states action and reaction are equal and opposite. In a rocket when hot gases come out of the rear with great force as a result of combustion, a force is created in the opposite direction. This takes the rocket forward. 234 What are the things necessary to start a fire? Heat, fuel and oxygen. 235 How many legs does a butterfly have? Six. 236 Who invented the aeroplane heavier than an air machine that could fly? Orville and Wilbur Wright. 237 Who invented the modern lift? Elisha Otis. 238 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. 239 Ancient Sumenans used to write on clay. How could this writing be preserved? By baking the tablets. This would remove the moisture from the tablets and harden them. 240 How big are the tusks of an Indian female elephant? Indian female elephants do not have tusks. 241 Bats cannot see. Then how do they move about? They emit sounds of low intensity, which are reflected from the objects around them. This helps the bats to move about. 242 How does a frog catch an insect? It throws out its tongue, which is sticky and catches the insects. 243 What is a Portuguese Man of War? A name commonly applied to jelly fish, found in tropical seas. 244 Why are oceans important to man? They enable man to travel to distant corners of the world. They also provide food, oil and minerals. 245 What is the transparent portion in front of the eyeball called? Cornea. 246 What is the meaning of the pecking order? Pecking order is an example of hierarchy among animals, particularly hens. In a coup containing hens and cocks, the seniormost cock can peck at all the other hens and cocks in the coup. A hen can peck at others weaker than it, but must permit pecking by senior members in the hierarchy. 247 Who made trains run by steam engine popular? George Stephenson 248 How are volcanoes caused? Deep under the crust of the earth is molten rock or lava, also called magma. It is under great pressure because of the intense heat around it and the weight of the earth's crust. When this hot boiling mass finds an outlet in the underside of the earth's crust, it comes through the surface as lava. 249 What is a male ant called? Drone. 250 How can a frog make such a loud sound? As the frog forces air from the lungs, vocal chords in the voice box (larynx) vibrate to make calls, distinctive of its species. The bulls of some species have air sacs, which help, increase the volume of the sound. 251 Who was the first man on the moon? Neil Armstrong. 252 What is peristalsis? Peristalsis is a type of movement occurring in the hollow organs of animals, which causes their contents to be pushed ahead. 253 What are the main differences between an Indian elephant and an African elephant? The African elephant is much larger in size. Its ears as well as tusks are larger than those of an Indian elephant. 254 What is it that silkworms weave around themselves? Cocoon. 255 Why did Dr. Lister use carbolic acid to cover wounds? To prevent infection. 256 What is the juice of the rubber plant called? Latex 257 Why does the ostrich eat sand or gravel? To digest its food. 258 Which discovery made soap-making a big industry? It was discovered (in 1787) that caustic soda can be made from common salt. Since soap is made from caustic soda and fat, manufacturing soap became cheaper. 259 Who invented the Gramophone? Thomas Alva Edison 260 Which is the largest living bird? Ostrich. 261 Why didn't the British plant rubber in England? Rubber grows only in tropical countries. 262 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. 263 What was called Penny-farthing? The cycle whose front wheel was much larger than the rear wheel. It was invented by James Starley. It was derisively named penny-farthing after the largest and smallest English copper coins of the period. 264 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. 265 Name the animal that has the largest eyes in the world? The Atlantic Giant Squid, about 30 cm wide. 266 Who invented the four-stroke Motorcar engine? Nikolaus Otto. 267 What are meteorites? They are rocks or pieces of rocks that enter the atmosphere and are usually burnt out before landing on earth. Some large meteorites can crash against the surface of the earth and cause damage. 268 What did ancient Romans think lightning was? Jupiter's weapon. 269 Are the soldier ants male or female? They are all female. 270 What is the nest of a penguin made of? Pebbles. 271 What are the characteristics of a parasitic plant? They cannot produce their own food and obtain food from other sources. 272 What keeps the sun so hot? A reaction similar to that of a hydrogen bomb takes place continuously in the sun. Two atoms of hydrogen fuse at high temperatures to form an atom of helium. Immense heat is released in this reaction. 273 What is meant by Binary System? We carry out everyday calculations, using the decimal system, with the numbers 1 to 9 and zero. The binary system uses only two numbers 0 and 1. An electric current can be switched on and off using off for 0 and on for 1. Any number can be represented in the binary system. 274 Which was the first spaceship launched by man? Sputnik-I, launched by the Russians 275 What kind of nests do owls build? They don't build nests. They use hollows in trees for laying eggs. 276 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. 277 Which Psychologist devised the IQ test? Alfred Binet. 278 Who discovered Radium? Pierre and Marie Curie. 279 What is the approximate temperature deep inside the sun? 14 million degrees C. 280 What are Epiphytic plants? Plants that grow on other plants for support. These plants however do not take nourishment from the host. 281 Sometimes the eagle spits out pellets from its mouth. What are they? Bones and fur of the prey that are left after the food is digested. 282 What does a ruminant mean? Ruminant is an animal that chews its cud and has a four-chambered stomach. When food is swallowed by a ruminant, it passes into the rumen or paunch, where it is stored, while the animal eats. Chewing and digestion are carried out at leisure. The food passes from the rumen to the reticulum, where it is formed into small masses and pushed up to the mouth to be chewed. When it is swallowed a second time it takes a different route. Gastric digestion takes place and the food passes into the intestine. 283 Who discovered the Planet Uranus? Sir William Herschel. 284 Who invented Television? John Logic Baird. 285 How do dolphins communicate with each other? By producing screeching sounds. 286 Who was the first woman to travel in space? Valentina Tereshkova. 287 What are clouds made of? Tiny droplets of ice or water. 288 What is the disease that causes dogs to turn mad? Rabies. 289 Who conducted the first controlled fission reaction (that led to the making of the atom bomb)? Enrico Fermi. 290 Which was the first satellite launched by India? Aryabhata, in 1975. 291 What is Dry Ice? Solid Carbon Dioxide. 292 Who invented the Radio? G. Marconi (Jagadis Chandra Bose has also been credited with this discovery but his claim has not been recognised). 293 What was the theory of the atom put forward by Rutherford? Rutherford put forward the theory that every atom consists of a tiny nucleus with a positive charge, surrounded by electrons. The electrons are far apart from the nucleus and from one another. 294 Of which element is diamond made of? Carbon. 295 The Pit Viper has poor eyesight. Yet it can locate its prey accurately. How? It has heat sensory cells in the pits between the eye and the nostril, which detect warm-blooded animals. 296 Who first propounded the theory of Evolution of Man? Charles Darwin. 297 From which elements is steel made? Iron and Carbon. 298 Which instrument is used for measuring humidity? Hygrometer. 299 If you speak loudly on the moon, approximately how far can your voice travel? Sound waves need a medium in which they can travel. The atmosphere on the moon is negligible. Hence your voice cannot travel any distance. 300 What is the difference between Toads and Frogs? Toads have a dry warty skin while frogs have a smooth moist skin.