Science-Class-8 DPP Talent Search Examinations

Each question has four alternatives marked (A), (B), (C) and (D), but only one of these alternatives is the correct answer. Find the correct answer. 1. Match the statements of Column-I and Column-II and tick-mark () the correct matching, given as one of the four alternatives A, B, C and D. Column-I Column-II (a) Wheat (i) plant fibre (b) Plant fibre (ii) jute (c) Jute (iii) cotton (d) Cotton (iv) wheat (e) Long vegetable fibre (v) rabi crop (f) Bread and biscuits (vi) kharif crop (A) (a) - v, (b) - ii, (c) - i, (d) - vi, (e) - iii, (f) - iv (B) (a) - vi, (b) - v, (c) - i, (d) - iv, (e) - iii, (f) - ii (C) (a) - v, (b) - iii, (c) - i, (d) - vi, (e) - ii, (f) - iv (D) (a) - vi, (b) - iii, (c) - i, (d) - v, (e) - ii, (f) - iv 2. The earth takes nearly 365 days to complete one revolution around the sun. If the orbit of the earth around the sun (supposed to be circular) is 1.5 × 1011m, then the orbital speed of the earth is nearly (A) 465 m/s (B) 30 km/s (C) 3,000 m/s (D) 60 km/s 3. Which one of the following statements is not correct about microorganisms ? (A) In agriculture, microorganisms are used to increase the soil fertility (B) Some microorganisms cause diseases in human beings, plants and animals (C) Microorganisms are used for making wines, curds, idli, bread, etc. (D) Source of antibiotics are microoganisms and these antibiotics are very effective against cold and cough 4. When a copper vessel is exposed to moist air for long, it acquires a dull green coating. This dull green coating is mixture of (A) copper hydroxide and copper chloride (B) copper chloride and copper carbonate (C) copper carbonate and copper hydroxide (D) copper sulphide and copper carbonate [2] 5. Sound is one of the greatest gifts nature has given to living beings. It is produced simply by vibrations in a medium. Sound helps us to communicate with one another and to enjoy music. In the following crossword, words connected with sound and hearing ability of humans are given, either along horizontal or along vertical lines. How many such words are there in the above crossword ? (A) 15 (B) 14 (C) 13 (D) 12 6. Which one of the following famous cities is not situated on the banks of river Ganga ? (A) Kanpur (B) Patna (C) Lucknow (D) Bhagalpur 7. Which one of the following statements is not correct ? (A) The axis of rotation of the earth is not perpendicular to the plane of its orbit, but is tilted. The change of seasons is due to this tilt (B) Formations of day and night on the earth are due to the rotation of the earth about its axis (C) Comets are not a planets, though these revolve around the sun in elliptical orbits, like other planets (D) Asteroids also revolve around the sun. These lie between the orbits of Jupiter and Saturn [3] 8. Fill in the blanks with proper words in the following paragraph and choose the correct option, given below. Manure is an organic ............. and is used as organic ............. in The manure contributes to the fertility of ............. by adding organic matter and ............., such as ............., that are trapped by ............. in the soil. Higher organisms then feed on fungi and bacteria in a chain of life that comprises the soil food web. (A) matter, fertilizer, plantation, agriculture, nutrients, nitrogen, bacteria (B) matter, fertilizer, agriculture, soil, nutrients, nitrogen, bacteria (C) matter, fertilizer, agriculture, soil, nitrogen, nitrates, bacteria (D) matter, fertilizer, agriculture, plants, nutrients, nitrogen, bacteria 9. Pole Star appears stationary to us. This is because (A) it is the only star which does not revolve (B) it is very far away and hence its relative motion is almost negligible (C) it lies along the axis of rotation of the earth (D) it lies along the line joining the centre of the earth and that of the sun 10. Which one of the following statements is not correct ? (A) Metals, in general, are sonorous, ductile and malleable (B) When zinc granules are added to copper sulphate solution, the colour of the solution changes from blue to brown (C) Copper does not react with dilute hydrochloric acid. However, reaction takes place only when heated strongly (D) Oxides of non-metals are acidic in nature 11. The density of one planet is very small and is less than that of even water. The name of this planet is (A) Saturn (B) Neptune (C) Uranus (D) Venus 12. One of the man-made fibre which is prepared only from coal, water and air is (A) rayon (B) nylon (C) acrylic (D) terylene [4] 13. Match the statements given in Column-I and Column-II tick-mark () the correct matching, given as one of the four alternatives A, B, C and D. Column-I Column-II (a) Non-metal which is essential for all living (i) chlorine beings, animals as well as plants (b) Non-metal, the deficiency of which produces (ii) phosphorus goitre in human beings (c) Non-metal which is used for water purification (iii) oxygen (d) Non-metal which is used in making fire (iv) nitrogen crackers (e) Non-metal used in fertilizers to enhance the (v) iodine growth of plants (A) (a) - iii, (b) - v, (c) - i, (d) - iv, (e) - ii (B) (a) - iii, (b) - v, (c) - i, (d) - ii, (e) - iv (C) (a) - iv, (b) - v, (c) - i, (d) - ii, (e) - iii (D) (a) - iii, (b) - v, (c) - ii, (d) - i, (e) - iv 14. The tip of the nail is made very sharp. This is done so that it can penetrate easily into wooden surface or wall. The penetration of the sharp-tipped nail becomes easier due to (A) increase in force at the tip (B) decrease in frictional force near the tip (C) increase in pressure at the tip (D) less work done, in this case 15. Tick-mark () the incorrect statement from the following. (A) Each sperm is a single cell with all the usual cell components (B) The transformation of the larva into an adult through drastic changes is called metamorphosis (C) Gametes  Embryo  Zygote  Foetus  Baby (D) In hydra, new individuals develop from buds. This method of asexual reproduction is called budding 16. Which one of the following forces is different from the other three ? (A) Gravitational force (B) Electrostatic force (C) Magnetic force (D) Frictional force [5] 17. Match the statements given in Column-I and Column-II tick-mark () the correct matching, given as one of the four alternatives A, B, C and D. Column-I Column-II (a) Irrigation (i) preparation of soil (b) Manuring (ii) separation of grains from chaff (c) Ploughing (iii) proper growth of plants (d) Sowing (iv) improving soil texture (e) Threshing (v) selection of seed (A) (a) - iii, (b) - iv, (c) - v, (d) - i, (e) - ii (B) (a) - iv, (b) - iii, (c) - i, (d) - v, (e) - ii (C) (a) - iii, (b) - iv, (c) - i, (d) - v, (e) - ii (D) (a) - iv, (b) - iii, (c) - ii, (d) - v, (e) - i 18. In which one of the following gases, atmospheric pressure (pressure of atmospheric air) in not working ? (A) Rising of water in a cloth when one of its ends is dipped into water (B) Rising of liquid (medicine) in an eye-dropper (C) Pumping out water from ground, using a hand-pump (D) When a lizard is running along the ceiling of a room 19. Fill in the blanks with proper words in the following paragraph and choose the correct option, given below. Now-a-days, the head of safety matchstick contains only antimony ................ and potassium ................ . The rubbing surface has powdered glass and a little ................ phosphorus (which is much less dangerous). When the matchstick is struck against the rubbing surface, some ................ phosphorus gets converted into ................ phosphorus. This immediately reacts with potassium ................ in the matchstick head to produce enough heat to ignite ................ ................ and start combustion. (A) bisulphide, chlorate, red, red, white, chlorate, antimony, bisulphide (B) trisulphide, chlorate, white, white, red, chlorate, antimony, trisulphide (C) trisulphide, dichlorate, red, red, white, dichlorate, antimony, trisulphide (D) trisulphide, chlorate, red, red, white, chlorate, antimony, trisulphide [6] 20. Match the statements of Column-I and Column-II and tick-mark () the correct matching, given as one of the four alternatives A, B, C and D. Column-I Column-II (a) Silver (i) metal commonly used in electrical batteries (b) Copper (ii) this metal and its alloys are commonly used for making aeroplanes and other aerospace articles (c) Zinc (iii) precious metal used in making ornaments and jewellary (d) Aluminium (iv) metal used for coating the surfaces of other metals to prevent corrosion (e) Tin (v) metal used for making wires to carry electric current (A) (a) - iii, (b) - v, (c) - i, (d) - iv, (e) - ii (B) (a) - iii, (b) - v, (c) - i, (d) - ii, (e) - iv (C) (a) - iii, (b) - v, (c) - iv, (d) - ii, (e) - i (D) (a) - iii, (b) - v, (c) - iv, (d) - i, (e) - ii 21. Dysentery and malaria are (A) viral diseases (B) bacterial diseases (C) fungal diseases (D) protozoan diseases 22. Which element is most abundant by mass in earth’s crust ? (A) Oxygen (B) Nitrogen (C) Iron (D) Silicon 23. Which one of the following is not associated with the frequency of sound ? (A) Pitch (B) Hertz (C) Loudness (D) Shrillness 24. Which one of the following statements is not correct ? (A) Deforestation may lead to global warming (B) Deforestation increases the chances of natural calamities such as floods and droughts (C) The plants and animals found in a particular area are termed fauna and flora of that area (D) Endemic species are those species of plants and animals which are found exclusively in a particular area [7] 25. After no-moon night, the moon again starts appearing at night for small duration and with small visible size (as crescent moon). The shape of such moon is (A) like , appearing in the west (B) like , appearing in the east (C) like , appearing in the east (D) like , appearing in the west 26. Which one of the following statements is not correct ? (A) Bacterial cell has a cell wall (B) During fertilization, the nuclei of the sperm and the egg fuse to form a single nucleus (C) IVF is associated with test-tube babies (D) Hydra reproduces by binary fission 27. Fill in the blanks with proper words in the following paragraph and choose the correct option, given below. When disease-carrying ................ enter our body, the body produces ................ to fight the ................ . The body also remembers how to fight the microbe if it ................ ................ . So, if dead or weakened microbes are ................ into to a healthy body, the body fights and ................ them by producing ................ ................ . The antibodies remain in the body and protect us from the disease-carrying microbes. This is how a vaccine works. Several diseases including cholera, tuberculosis, small pox and hepatitis are by vaccination. (A) microbes, antibodies, invader, enters again, introduced, tames, suitable antibodies, treated (B) microbes, antibodies, invader, enters again, introduced, kills, suitable antibodies, prevented (C) microbes, antibodies, invader, enters again, produced, kills, suitable antibodies, prevented (D) microbes, antibodies, invader, enters again, introduced, kills, suitable antibodies, cured [8] 28. Two mirrors OM and OM´ are inclined with each other at an angle of 80°. A ray of light is incident on mirror OM making an angle of 40° with its surface. What angle will the reflected ray from mirror OM´ will make with mirror OM´ ? (A) 70° (B) 60° (C) 50° (D) 40° 29. During persistent thunderstorm and lightning, which one of the following is not advisable ? (A) If you are travelling in a car or bus, remain in the car or bus; do not run out side for safety (B) If you are in the house, unplug or disconnect electrical appliances like computer, TV, refrigerator, etc. (C) If you are in forest, take shelter under the shorter tree (D) Switch off electric lights and use candle light instead in the house 30. Which one of the following is the correct flow chart of crop production ? (A) Ploughing the field  Preparation of soil  Sowing  Irrigation  Manuring  Harvesting  Storing (B) Ploughing the field  Preparation of soil  Manuring  Sowing  Irrigation  Harvesting  Storing (C) Ploughing the field  Preparation of soil  Sowing  Manuring  Irrigation  Harvesting  Storing (D) Ploughing the field  Preparation of soil  Irrigation  Sowing  Manuring  Harvesting  Storing 31. Only a handful of microorganisms are harmful while most of them are beneficial. So many antibiotics are made from bacteria and fungi. Many scientists, working on the culture of disease-causing bacteria have developed medicines and vaccines for various diseases. The vaccine for smallpox was developed by (A) Edward Jenner (B) Robert Koch (C) Alexander Fleming (D) Robert Hooke [9] 32. Match the statements of Column-I and Column-II and tick-mark () the correct matching, given as one of the four alternatives A, B, C and D. Column-I Column-II (a) Acrylic (i) its fabrics do not wrinkle easily (b) Nylon (ii) artificial silk, made from wood pulp (c) Polyester (iii) resembles wool, more durable and popular than natural fibre (d) Rayon (iv) it is used for non-stick cookwares (e) Teflon (v) its threads are stronger than steel wire, so it is used for making parachutes and ropes for climbing (A) (a) - iii, (b) - v, (c) - ii, (d) - i, (e) - iv (B) (a) - ii, (b) - v, (c) - i, (d) - iii, (e) - iv (C) (a) - iii, (b) - v, (c) - i, (d) - ii, (e) - iv (D) (a) - ii, (b) - i, (c) - v, (d) - iii, (e) - iv 33. The great advantage of natural gas is that it can be used directly for burning in homes and factories. It can also be stored under high pressure as compressed natural gas (CNG) and then can be transported. The main constituent of the natural gas is (A) ethane (B) methane (C) hydrocarbons (D) petroleum gas 34. Fill in the blanks with proper words in the following paragraph and choose the correct option, given below. With a microscope of large magnification, we can see a smaller spherical body in the nucleus of a cell. It is called ................ . In addition, the nucleus contains ................ structures called ................ . These carry ................ and help in inheritance and transfer of ................ from the parents to the ................ . (A) nucleolus, jelly-like, chromosomes, genes, characters, offspring (B) nucleolus, thread-like, chromoplasts, genes, characters, offspring (C) nucleolus, thread-like, chromosomes, codes, characters, offspring (D) nucleolus, thread-like, chromosomes, genes, characters, offspring [10] 35. Match the statements of Column-I and Column-II and tick-mark () the correct matching, given as one of the four alternatives A, B, C and D. Column-I Column-II (a) Cat (i) oviparous (b) Hen (ii) metamorphosis (c) Fish (iii) viviparous (d) Frog (iv) external fertilization (A) (a) - iii, (b) - i, (c) - iv, (d) - ii (B) (a) - iii, (b) - i, (c) - ii, (d) - iv (C) (a) - i, (b) - iii, (c) - iv, (d) - ii (D) (a) - iii, (b) - ii, (c) - i, (d) - iv 36. Antibiotic penicillin was developed from Penicillium notatum ( a fungus). This discovery of penicillin was done by (A) Robert Hooke (B) Alexander Fleming (C) Robert Koch (D) Louis Pasteur 37. In which of the following cases, the resultant force is not zero ? (A) When a helium-filled balloon is stationary at some height above the ground (B) When rain drops are falling towards the earth with uniform speed (C) When a satellite is moving around the earth, in a circular path, with uniform speed (D) When a cork is floating in water kept in a bucket 38. Nitrogen gas is extensively used in food packaging to keep food fresh. This is because nitrogen gas (A) acts as germicide and does not allow any bacteria to grow (B) is abundantly available in nature and hence can be collected and used easily (C) provides an unreactive environment in which bacteria cannot grow (D) is a bad conductor of heat and so does not allow heat exchange between surroundings and packaged food 39. Through a massive vaccination programme, which one of the following diseases has been eradicated ? (A) Smallpox (B) Chicken-pox (C) Rabies (D) Polio [11] 40. All cells are bound by a membrane called plasma membrane. It encloses a liquid substance known as protoplasm. More than ninety-five percent of protoplasm by its weight is made of the compounds of four elements, namely (A) hydrogen, carbon, sulphur and nitrogen (B) hydrogen, carbon, nitrogen and chlorine (C) carbon, hydrogen, chlorine and oxygen (D) carbon, hydrogen, nitrogen and oxygen [12] ANSWERS : CLASS VIII SCINECE 1 C 2 B 3 D 4 C 5 B 6 C 7 D 8 B 9 C 10 C 11 A 12 B 13 B 14 C 15 C 16 D 17 C 18 A 19 D 20 B 21 D 22 A 23 C 24 C 25 B 26 D 27 B 28 B 29 D 30 C 31 A 32 C 33 B 34 D 35 A 36 B 37 C 38 C 39 A 40 D [13]