Science-Class-10 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. In the following circuit, the current flowing through the resistance of 3, would be Rough Work (A) 2.0 A (B) 1.5 A (C) 1.2 A (D) 1.86 A 2. 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) Iris (i) light enters the eye through it (b) Retina (ii) regulates and controls the amount of light entering the eye (c) Cornea (iii) light-sensitive screen of the eye where the image is formed (d) Ciliary muscle (iv) controls the size of the pupil (e) Pupil (v) enables eye to adjust its focal length (A) (a) - ii, (b) - iii, (c) - i, (d) - v, (e) - iv (B) (a) - iv, (b) - iii, (c) - i, (d) - v, (e) - ii (C) (a) - iv, (b) - iii, (c) - ii, (d) - v, (e) - i (D) (a) - ii, (b) - iii, (c) - iv, (d) - v, (e) - i [2] 3. When sufficient amount of methane burns with two moles of oxygen, which one of the following are produced ? (A) One mole of carbon dioxide and one mole of water (B) One mole of carbon dioxide and two moles of water (C) Two moles of carbon dioxide and one mole of water (D) Two moles of carbon dioxide and two moles of water 4. The concentration of [H3O+] in a solution is 1 × 10–5 M. at 25ºC. The [OH–] concentration of the solution would be (A) 1 × 10–5 (B) 1 × 10–7 (C) 1 × 10–9 (D) 1 × 10–14 5. Which one of the following has the largest atom ? (A) Carbon (B) Beryllium (C) Boron (D) Oxygen 6. In a food chain, only 10 percent of energy is transferred from one trophic level to another. In the food chain : Grass  Insects  Sparrow  Hawk how much energy would a sparrow get if grass has ten thousand joules of energy ? (A) 10° J (B) 101 J (C) 102 J (D) 103 J 7. Gastric juices are secreted by the stomach. The correct contents of these juices are : (A) hydrochloric acid, trypsin, gastric lipase (B) hydrochloric acid, amylase, gastric lipase (C) hydrochloric acid, amylase, pepsin (D) hydrochloric acid, pepsin, rennin Rough Work [3] 8. Two plane mirrors OA and OB are inclined at an angle of 80°, as shown. A horizontal ray of light IPA, parallel to mirror OB, is incident on mirror OA, falling at A. After reflection at this mirror, the ray falls on the other mirror at B. From the second mirror, the ray is reflected along BE. The angle between the incident ray and finally reflected ray i.e., APE would be Rough Work (A) 140° (B) 160° (C) 120° (D) 150° 9. The magnification of image of small object, formed by a concave mirror is +2. If the focal length of the concave mirror is 30 cm, then the distance of the small object from the mirror should be (A) 10 cm (B) 20 cm (C) 15 cm (D) 25 cm 10. During sexual reproduction, which of the following activities do not take place ? (A) Sperms are formed in the testes of male (B) Eggs are formed in the ovaries of female (C) The egg is first implanted in the lining of uterus and then fertilized (D) The growing embryo gets nutrition from the blood of mother through placenta [4] 11. Tick-mark() the incorrect statement from the following. (A) When acetic acid reacts with sodium carbonate, the main product is sodium ethanoate (B) When methane reacts with chlorine only chloromethane is formed (C) When unsaturated hydrocarbon reacts with hydrogen in the presence of a suitable catalyst, the product formed is saturated hydrocarbon (D) When methane burns, then only water and carbondioxide are formed 12. The rate of a reaction can be increased by (A) decreasing temperature (B) using less amount of reactants (C) using a catalyst (D) all of the above 13. Nutrition of animals is of different types. Some eat plants, some eat insects, some eat other animals and some eat both plants and animals. Match the statements of Column I and Column II and the tick-mark() the correct matching, given as one of the four alternatives A, B, C and D. Column I Column II (a) Deer (i) carnivore (b) Lion (ii) parasite (c) Lizard (iii) herbivore (d) Human being (iv) insectivore (e) Tapeworms (v) omnivore (A) (a) - iii, (b) - i, (c) - ii, (d) - v, (e) - iv (B) (a) - v, (b) - i, (c) - iv, (d) - iii, (e) - ii (C) (a) - iii, (b) - i, (c) - iv, (d) - v, (e) - ii (D) (a) - iii, (b) - i, (c) - v, (d) - ii, (e) - iv Rough Work [5] 14. Tick-mark() the incorrect statement from the following. (A) –2.5 D is the power of a concave lens of focal length 40 cm (B) A human being has a horizontal field of view of about 120° with one eye and of about 180° with both the eyes (C) Defect in the eye produced due to gradual weakening of the ciliary muscles and diminishing flexibility is called presbyopia (D) The path of a beam of light passing through a true solution is not visible 15. A current of 0.5 A is drawn by a filament of an electric bulb for 8 minutes. Find the number of electrons that cross any cross-section of the filament during the time of flow of current through it. (A) 1.5 × 1021 (B) 1.5 × 1020 (C) 1.6 × 1021 (D) 1.6 × 1020 16. The white silver chloride turns grey in sunlight. This is because (A) silver chloride reacts with carbon dioxide present in the atmosphere (B) silver chloride reacts with oxygen present in the atmosphere (C) silver chloride decomposes into silver and chlorine (D) silver chloride gets polluted in the atmosphere 17. What is the formula of the ion that has 16 protons and 18 electrons ? (A) Ar2+ (B) S2– (C) Ar2– (D) S2+ Rough Work [6] 18. The growth of plants is sensitive to light, water and gravity. Some kind of movements, in response to these, are shown as the plants grow. Which one of the following statements is not correct ? (A) The shoots bend towards light (B) The roots bend towards the centre of gravity, as these grow (C) The roots bend towards light, as these grow (D) The shoots bend away from the centre of gravity 19. Which one of the following metals in its salt cannot be displaced by zinc ? (A) Copper (B) Silver (C) Lead (D) Calcium 20. IUPAC name of the compound (A) hexanoic acid (B) methylpentanoic acid (C) 2-methylpentanoic acid (D) 3-methylpentanoic acid CH3CH2CHCH2COOH is | CH3 21. Food is digested in our body by the action of enzymes. The enzymes digest different components of food specifically. Lipase acts on which one of the following ? (A) Proteins (B) Fats (C) Carbohydrates (D) Starch 22. Pancreas secretes pancreatic juices which contain digestive enzymes like trypsin, amylase and lipase. Tick-mark() the incorrect statements from the following. (A) Trypsin acts on proteins and converts them into peptides or aminoacids (B) Lipase acts on starch and converts it into sugar (C) Amylase acts on carbohydrates and converts them into glucose (D) Lipase acts on emulsified fats and converts them into fatty acids [7] 23. 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) Moving charge (i) Fleming’s right-hand rule (b) Force on current-carrying (ii) generator conductor in a uniform magnetic field (c) Electric current (iii) electric current (d) Induced currents (iv) magnetic field (e) Moving magnet (v) Fleming’s left-hand rule (A) (a) - iv, (b) - i, (c) - ii, (d) - v, (e) - iii (B) (a) - iii, (b) - v, (c) - ii, (d) - i, (e) - iv (C) (a) - iv, (b) - v, (c) - i, (d) - ii, (e) - iii (D) (a) - iv, (b) - v, (c) - ii, (d) - i, (e) - iii 24. Silver articles become black after some time, when exposed to air. This is because silver reacts with (A) carbon dioxide present in the atmospheric air (B) oxygen present in the atmospheric air (C) chlorine present in the atmospheric air (D) sulphur present in the atmospheric air 25. Tick-mark() the incorrect statement from the following. (A) As we go from left to right in a period in the periodic table, the atomic number increases (B) As we go from left to right in the periodic table, the radius of the atom of the element increases (C) As we go down in a group in the periodic table, the valency of the element remains the same (D) The oxides of the elements of first group in a periodic table are highly alkaline [8] 26. Match the scientists and their fields of work / inventions and tick-mark() the correct matching, given as one of the four alternatives A, B, C and D. Column I Column II (a) Measurement of electric current (i) Michael Faraday (b) Measurement of magnetic fields (ii) Alessandro Volta (c) Invention of electric bulb (iii) Andre Marce Ampere (d) Invention of electric cell (iv) Thomson Alwa Edison (e) Electromagnetic induction and (v) Hans Christian Oersted induced currents (A) (a) - iii, (b) - v, (c) - iv, (d) - ii, (e) - i (B) (a) - iii, (b) - v, (c) - iv, (d) - i, (e) - ii (C) (a) - iii, (b) - iv, (c) - v, (d) - ii, (e) - i (D) (a) - iii, (b) - iv, (c) - ii, (d) - v, (e) - i 27. Which one of the following is not related to the ovaries of the female ? (A) Estrogen (B) Adrinaline (C) Corpus luteum (D) Progesterone 28. Irregular or diffused reflection of light is called scattering. The colour of the scattered light depends on the size of the scattering particles. Which one of the following phenomenon, observed in nature, is not due to scattering of light ? (A) Appearance of blue sky (B) Appearance of red sun while rising and setting (C) Formation of rainbow in rainy season (D) Sea water appears to be blue 29. In the extraction of metals from their ores, we some times reduce their oxides with the help of coke. Oxide of which one of the following metals cannot be reduced by the coke ? (A) Aluminium (B) Iron (C) Zinc (D) Lead [9] 30. The atomic numbers of aluminium, sodium, zinc, argon and calcium are 18, 13, 11, 20 and 30 (not in order of these elements). Which one of the following is the correct order of elements with increasing atomic number ? (A) Sodium, aluminium, calcium, argon and zinc (B) Sodium, aluminium, argon, zinc and calcium (C) Sodium, aluminium, argon, calcium and zinc (D) Sodium, aluminium, calcium, zinc and argon 31. Tick-mark() the correct sequence of flow of air to lungs in our body. (A) Nose  Bronchi  Trachea  Alveoli  Broncheoles (B) Nose  Alveoli  Trachea  Bronchi  Broncheoles (C) Nose  Trachea  Bronchi  Broncheoles  Alveoli (D) Nose  Trachea  Broncheoles  Bronchi  Alveoli 32. Tick-mark() the correct statement from the following. (A) Reflex arcs are formed in mid brain (B) Reflex arcs are formed in hind brain (C) Reflex arcs are formed in fore brain (D) Reflex arcs are formed in spinal cord 33. Which one of the following relations is not true ? (A) joule = watt × second (B) watt = volt × ampere (C) coulomb = ampere × second (D) Ampere = volt × ohm 34. Pollen grains are present in which part of the flower ? (A) Stigma of pistil (B) Ovary of pistil (C) Anther of stamen (D) Filament of stamen [10] 35. Fill in the blanks with proper words in the following paragraph and choose the correct option. We need to use our resources carefully, because these are not and the human population is increasing at a ............... rate. The management of natural resources require ............... perspective so that these last for the ............... to come and not nearly exploit for short term gains. The management of resources should also ensure ............... distribution of resources for the benefit of all and not a few rich and people. (A) unlimited, uncontrollable, thoughtful, generations, satisfactory, deprived (B) unlimited, unpredictable, long-term, generations, beneficial, trading (C) unlimited, tremendous, long-term, generations, equitable, powerful (D) unlimited, tremendous, balanced, generations, convincing, ruling 36. Maintaining the posture and balancing of body is controlled by which one of the following parts of the nervous system ? (A) Hypothalamus (B) Cerebellum (C) Spinal cord (D) Mid brain 37. During the process of photosynthesis, light is required by the chlorophyll for which one of the following specific purpose ? (A) To split water into hydrogen and oxygen (B) To split carbondioxide into carbon and oxygen (C) To split some molecules of glucose to produce oxygen (D) To combine carbon, hydrogen and oxygen to form glucose 38. A fuse protects circuits and appliances by stopping the flow of undesirable high electric current. The fuse is placed in series with appliance or device and is an alloy of desirable elements such that (A) alloy of the fuse should have large resistance and high melting point (B) alloy of the fuse should have small resistance and low melting point (C) alloy of the fuse should have small resistance and high melting point (D) alloy of the fuse should have large resistance and low melting point [11] 39. Which one of the following is not correct about the magnetic lines of force ? (A) Two magnetic lines of force never intersect or cut each other (B) The magnetic lines of force are circular around a wire carrying current (C) The magnetic lines of force lie only outside a magnet but not inside it (D) The magnetic lines of force are parallel in a region where magnetic field is uniform 40. Sustainable development encourages forms of growth that (A) preserves the resources for future generations (B) meet the current basic needs of humans with minimum environmental damage (C) encourage business, leading to economic growth (D) encourage all round development with optimal exploitation of the environment [12] ANSWERS CLASS - X SCINECE 1 A 2 B 3 B 4 C 5 B 6 C 7 D 8 B 9 C 10 C 11 B 12 C 13 C 14 B 15 A 16 C 17 B 18 C 19 D 20 D 21 B 22 B 23 D 24 D 25 B 26 A 27 B 28 C 29 A 30 C 31 C 32 D 33 D 34 C 35 C 36 B 37 A 38 D 39 C 40 B [13]