Science Cinch

Sound waves are machanical waves. Sound is produced in the form of a pressure wave. When an object vibrates, it causes the surrounding air molecules to vibrate, initiating a chain reaction of sound wave vibrations throughout the medium. So, in order for sound to travel, there has to be something with molecules for it to travel through. On Earth, sound waves travels to your ears by vibrating air molecules but in deep space, the large empty areas between stars and planets, there are no molecules to vibrate. So, there is no sound there.

A magnet will always point North-South direction, because it is attracted by the north and south magnetic poles of the planet Earth. This property is used in a compass. A small needle-like magnet with its north and south poles marked is balanced on a pivot. The pivot is placed in the centre of a card with all the directions (or points of the compass) marked on it. If a traveller or person positions the compass so that the needle lies along the north-south line on the card, he can read off the direction in which he is going. Compass is very useful. For example, long ago in past, sailors of all around the World were navigate by using the Sun’s position in Daytime and Star’s position in Night time. But, sometimes, it was too cloudy for them to see the Sun or the Stars and so they did not know which way they have to go. The compass revolutionized sea travel because the sailors could find their way whatever the weather is. A compass needle points to the Earth`s magnetic poles. The navigator

Q. 1. Where the hormones named insulin and glucogen are secreted? (a). Liver (b). Stomach (c). Pancreas (d). Duodenum Q. 2. Cuscutta is which type of organism? (a). Autotrophic (b). Heterotrophic (c). Parasitic (d). Saprophytic Q. 3. The name of excretory organ of earthworm is (a). Kidney (b). Flame cell (c). Nephridia (d). None Q. 4. Flame cell is a type of excretion unit. In which it is found? (a). Amoeba (b). Sponge (c). Worms (d). All above Q. 5. What the record of heart beating is called? (a). ECG (b). EEG (c). PET (d). MRI Q. 6. In which type of blood group there are both type of antigens? (a). A (b). B (c). AB (d). O Q. 7. What is the valve of refractive index of dense flint glass? (a). 1.65 (b). 1.6 (c). 1.61 (d). 1.63 Q. 8. What is the complementary colour for red colour? (a). Magenta (b). Cyan (c). Yellow (d). Blue Q. 9. Name two planets nearest to Sun instead of

Q. 1. What is the name of respiratory organs in grasshopper? (a). Lungs (b). Gills (c). Skin (d). Trachea Q. 2. Food is absorbed in (a). Stomach (b). Oesophagus (c). Small intestine (d). Anus Q. 3. The number of digestive glands found in human are (a). One pair (b). Three pairs (c). Six pairs (d). Seven pairs Q. 4. A preservative gas is (a). Co 2 (b). SO 2 (c). HCl (d). None Q. 5. The cheapest acid is (a). HCl (b). HNO 3 (c). H 2 SO 4 (d). None Q. 6. The most commonly used metal is (a). Gold (b). Copper (c). Iron (d). Silver Q. 7. The number of metals which are found in nature is (a). 20 (b). 112 (c). 70 (d). 118 Q. 8. The rate of respiration in plants as compared with animals is (a). More (b). Equal (c). Higher   (d). Smaller Q. 9. What is the length of alimentary canal of human? (a). 3m (b). 6m (c). 4m (d). 9m Q. 10. From where digestion of protein starts?

Q. 1. Natural satellite of Earth is (a). Sun (b). Moon (c). Mars (d). Star Q. 2. What are the main types of mirrors? (a). 5 (b). 9 (c). 3 (d). 2 Q. 3. The phenomenon of coming back of light after striking a surface is known as (a). Reflection (b). Reflective index (c). Refraction (d). dispersion Q. 4. The mid-point in the spherical is known as (a). Pole (b). Optical centre (c). Principal focus (d). None Q. 5. Our eyes are most sensitive to which colour of light? (a). Red colour (b). Green colour (c). Orange colour (d). Blue colour Q. 6. Human kidney are (a). Bean shaped (b). Spindle shaped (c). Slipper shaped (d). None Q. 7. Heart of heat is (a). SA node (b). AV node (c). Bundle of His (d). None Q. 8. Name the four blood groups in human being (a). A, B, C, D (b). A, B, D, F (c). A, B, AB, O (d). A, B, AB, C Q. 9. What is the respiratory organs in cockroach? (a). Lungs (

Q. 1. For which metals the distillation method of refining is used? (a). Mercury and zinc (b). Tin and lead (c). Iron and aluminium (d). Copper and zinc Q. 2. What is chemical formula of bauxite? (a). Al 2 O 3 (b). Al 2 O 3 .2H 2 O (c). Na 3 Al F 6 (d). None Q. 3. What is the melting point of alumina? (a). 2340K (b). 2348K (c). 2350K (d). 2446K Q. 4. Which is used as fungicide? (a). Chlorine (b). Sulphur (c). Carbon (d). Phosphorus Q. 5. Which metal is best conductor of heat? (a). Iron (b). Silver (c). Copper (d). Zinc Q. 6. Photosynthesis is which type of process? (a). Physical (b). Chemical (c). Biochemical (d). Biotic Q. 7. Pancreatic juice is secreted from where..? (a). Stomach (b). Liver (c). Gall bladder (d). Pancreas Q. 8. Which organ is of U-shaped in human digestive system? (a). Stomach (b). Duodenum (c). Oesophagus (d). Liver Q. 9. How many satellites does Jupiter

Q. 1. pH of human urine is (a). 7 (b). 8 (c). 5 (d). 6 Q. 2. A transparent medium bounded by three surfaces is called, (a). Lens (b). Prism (c). Glass slab (d). None of above Q. 3. What is done by a highly polished surface (or mirror) falling the light on its surface? (a). Reflected (b). Refracted (c). Reflected and refracted (d). None of above Q. 4. How many colours are there in white light of the Sun? (a). 8 (b). 6 (c). 3 (d). 7 Q. 5. Who sustains life on Earth? (a). Moon (b). Galaxies (c). Stars (d). Sun Q. 6. The 1 st planet to be discovered is (a). Pluto (b). Earth (c). Mars (d). Neptune Q. 7. Bile juice is secreted from where? (a). Stomach (b). Liver (c). Pancreas (d). Gall bladder Q. 8. In which of the following the exchange of gases take place through skin? (a). Fish (b). Frog (c). Earthworm (d). None of above Q. 9. How we get energy? (a). By digestion of foods