Formatting page ...
VIBGYOR RISE Preliminary Examination 2021-2022 SCIENCE Grade: X Max. Marks :40 Date: 4/10/2021 Time Allowed: 90min INSTRUCTIONS: This question paper contains 50 questions. All Questions are compulsory. Write the correct option in the space provided. At any time during the test you can change your answer. The intended marks for the questions are given alongside the questions. Click the "submit" button to submit your paper only after you have completed and verified your paper. Q1) 1. Multiple Choice Questions: [7] A light ray is incident on a rectangular glass slab makes an angle of 30 with [1] the surface of the slab. The angle between the ray coming out of the slab and the normal to the face of rectangular slab from which it comes out is a) 90 b) 30 c) 60 d) 0 2. The bluish colour of water in deep sea is due to a) the presence of algae and other plants found in water b) reflection of sky in water c) absorption of light by the sea d) scattering of light 1 [1] 3. The refractive index of water is 1.5. The speed of light in water will be [1] a) 1.33 x 108 m/s b) 3 x 108 m/s c) 2.66 x 108 m/s d) 2.0 x 108 m/s 4. An object is kept at a 60 cm in front of a plane mirror. If the mirror is now [1] moved 25 cm away from the object, how does the image shift from its previous position? a) 50 cm away b) 35 cm towards c) 85 cm away d) 35 cm away 5. A spherical mirror and a thin spherical lens have each focal length of -15 cm. [1] The mirror and the lens are likely to be a) Both concave b) Both convex c) The mirror is concave and the lens is convex d) The mirror is convex and the lens is concave 6. Which of the materials cannot be used to make a lens? [1] a) Water b) Glass c) Plastic d) Clay 7. The figure alongside shows the image of a clock as seen in a plane mirror. The correct time is 2 [1] a) 10:10 b) 1:50 c) 2:10 d) 11:20 8. A milk man adds a very small amount of baking soda to fresh milk . Why? [1] a) To increase the rate of fermentation b) To decrease the rate of fermentation c) To increase its quality d) To make paneer 9. Many salts absorbs water from atmosphere. This property is called [1] a) deliquescence b) efflorescence c) hydration d) addition 10. Which metal will start melting when kept on palm? [1] a) Potassium b) Sodium c) Cesium and Gallium d) Gallium and Mercury 11. Oxidation involves [1] 1) gain of electrons 2) loss of electrons 3 3) addition of oxygen or electronegative element 4) removal of hydrogen or electropositive element a) 1,2,3 b) 2,3,4 c) 1,3,4 d) 1,2,4 12. The electronic configurations of three elements X,Y,Z are X -2,2 ; Y -2,8,7 ; [1] Z -2,8,2. Which of the following is correct? a) X is a metal b) Y is a metal c) Z is a non-metal d) Y is a non-metal and Z is a metal 13. Identify x , y and z in the following balanced reaction x Pb(NO3)2 [1] y PbO + z NO2 + O2 a) 2,4,2 b) 2,2,4 c) 2,4,4 d) 4,2,2 14. The atomic number of an element X is 19. The number of electrons in its ion [1] X+ will be a) 18 b) 19 c) 20 d) 21 15. One of the following does not inject an acidic liquid into the skin through its sting. This is a) Honey bee 4 [1] b) Ant c) Wasp d) Nettle leaf hair 16. The part of digestive system where no digestion takes place is [1] a) ileum b) stomach c) mouth d) oesophagus 17. The fermentation of glucose by yeast normally yields [1] a) alcohol, CO2 and 36 ATP b) H2O, CO2 and 36 ATP c) alcohol, CO2 and 2 ATP d) lactic acid, CO2 and 36 ATP 18. Coagulation of blood in a cut or wound is brought about by [1] a) Plasma b) Platelets c) WBC d) RBC 19. During the deficiency of oxygen in tissues of human beings, pyruvic acid is converted into lactic acid in a) cytoplasm b) chloroplast c) mitochondria d) golgi body 5 [1] 20. In which of the following are the largest amounts of nitrogen excreted from a [1] mammalian body? a) breath b) sweat c) urine d) faeces Case When the coin is under water, then due to the refraction of light, a virtual image of the coin is formed which is slightly above its actual position nearer to water surface as shown in the figure. This is because the light rays are coming from coin and then go from water to air, they deviate from their path and get deflected away from the normal. Backward extension of these refracted ray appear to meet at point I , the image of the coin. 21. The property which remains unchanged during refraction of light is: [1] a) wavelength b) speed of light c) frequency d) Colour of the light 22. A torch submerged in water sends a light beam towards the surface of water at an angle of incidence of 30 . The angle of refraction in air is: a) Greater than 30 b) Less than 30 c) Equal to 30 6 [1] d) Equal to 0 23. We can distinguish [1] a medium to be optically rarer or optically denser on the basis of: a) Bending of light b) Velocity of light in the medium c) Refractive index of the medium d) All of the above Case After studying the concept of reflection, refraction, dispersion and deviation of white light by spherical water droplets, Sonia understands how the light changes its direction and spreads out when it enters or exits water droplets. With the help of these concepts , she got an idea for creating the rainbow in the house. 24. Which of the following phenomenon does not occur during the formation of [1] rainbow? a) Reflection b) Deviation c) Induction d) Dispersion 25. The necessary condition(s) for the formation of a rainbow is/are [1] a) Presence of water droplets in air and sunlight shining from behind. b) Presence of water droplets in air and sun must be in the front of observer. c) Observer must stand with his back towards the sun and presence of dry atmosphere. d) Observer must stand with his back towards the moon in the night and presence of moisture in the atmosphere 26. When white light is passed through a hollow prism: a) only dispersion occurs b) only deviation occurs 7 [1] c) both dispersion and deviation occurs d) neither dispersion nor deviation occurs Case A student wants to project the image of a candle flame on a screen 60 cm in front of a mirror by keeping the flame at a distance of 15 cm from its pole. 27. Suggest the type of mirror he should use: [1] a) Convex mirror b) Plane mirror c) Concave mirror d) None of the above 28. Find the magnification of the image produced. [1] a) -4 b) +4 c) -900 d) +900 Case 29. Our body needs to remove the wastes that build up from cell activities and from digestion. If these wastes are not removed, then our cells can stop working and we can get very sick. The organs of excretory system consists of a pair of kidneys, a pair of ureters, a urinary bladder and a urethra. Each kidney is made up of nearly one million complex tubular structures called nephrons. The formation of urine involves various processes that takes place in the different parts of the nephrons. Each nephron consists of a cup-shaped upper end called Bowman s capsule containing a bunch of capillaries called glomerulus. Bowman s capsule leads to tubular structure, proximal convoluted tubule, loop of Henle and distal convoluted tubule which ultimately joins the collecting tubule. Glomerular filtrate is first collected by a) proximal convoluted tubule [1] b) distal convoluted tubule c) Bowman s capsule d) loop of Henle 30. The outline of principal events of urination is given below in random order. I. Stretch receptors on the wall of urinary bladder send signals to the CNS. II. The bladder fills with urine and become distended. 8 [1] III. IV. Micturition CNS passes on motor messages to initiate the contraction of smooth muscles of bladder And simultaneous relaxation of urethral sphincter. The correct sequence of the events is a) I II III IV b) IV III II I c) II I IV III d) III II I IV 31. Urine formation occurs through [1] a) Ultrafiltration, reabsorption, secretion and osmosis. b) Secretion, osmosis, ultrafiltration and reabsorption. c) Only filtration and absorption. d) Only osmosis and secretion. Case The heart is a pumping organ that receives blood from the veins and pumps it into the arteries. It is situated in the thoracic cavity which lies above the diaphragm between the two lungs. It is enclosed in a double walled membraneous sac. 32. The double walled membraneous sac within which the heart is enclosed is [1] called a) Vena cava b) Atria c) Diaphragm d) Pericardium 33. The pacemaker of human heart is located at: [1] a) Upper wall of right ventricle b) Lower wall of right ventricle c) Upper wall of right atrium d) Lower wall of right atrium 34. Which of the following statement is true? [1] 9 a) Heart valves are tricuspid b) Heart valves are bicuspid c) Valves on the right side of the heart are tricuspid and that on left side are bicuspid. d) Valves on the right side of the heart are bicuspid and that on left side are tricuspid. Case Taj Mahal, the great wonder of the world, is made of white marble which is composed of calcium. About 60 years ago, it was discovered that this monument is eaten away by acid rain. The Archaeological survey of India, that looks after this building of historical importance is of the opinion that the atmospheric pollution due to Mathura refinery may be a major cause of acid rain in and around the monument. Normal rain is slightly acidic. Acid rain is more acidic than normal rain. 35. Which of the following is correct formula of compound present in marble? [1] a) CaO b) Ca(OH)2 c) CaCO3 d) CaSO4 36. The gas formed when acid rain falls on Taj Mahal: [1] a) CO b) CO2 c) SO2 d) NO2 37. Rain is called acid rain, if its pH value is: [1] a) 3 b) 6.5 c) 7.8 d) 9.7 Case An element is a pure substance made up of same kind of atoms. At present, 10 nearly 118 elements are known but all of them do not occur free in nature, some of them have been synthesized by artificial methods, they are mainly classified as metals and non-metals. The easiest way to start grouping substances is by comparing their physical properties. Metals, in their pure state, have a shining surface. This property is called metallic lustre. Metals are generally hard, some are used for making cooking vessels. 38. Metals generally are [1] a) reducing agents b) oxidizing agents c) both reducing and oxidizing agents d) None of the above 39. The metal that reacts with cold water is [1] a) Mercury b) Sodium c) Zinc d) Tungsten 40. Metal present in chlorophyll is [1] a) Iron b) Copper c) Magnesium d) Cobalt Case P,Q and R are three elements which undergo chemical reactions according to the following equations. (1) P2O3 + 2Q (2) 3RSO4 + 2Q (3) 3RO + 2P 41. Q2O3 + 2P Q2(SO4)3 + 3R P2O3 + 3R The most reactive and least reactive elements are: a) Q and P b) Q and R c) R and Q d) R and P 11 [1] 42. The type of reaction is: [1] a) Displacement reaction b) Combination reaction c) Neutralization reaction d) Double displacement reaction 43. Choose the correct statement: [1] a) Zinc and lead are more reactive elements than copper. b) Zinc and lead are less reactive elements than copper. c) Zinc and copper are more reactive elements than lead. d) Lead and copper are more reactive elements than zinc. Following question consist of two statements - Assertion (A) and Reason (R). Answer the question selecting the appropriate option given below: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true but R is not the correct explanation of A. (c) A is true but R is false. (d) A is false but R is true. 44. Assertion (A): The focal length of convex mirror will increase, if the mirror is [1] placed in water. Reason (R): The focal length of a convex mirror of radius R is equal to 2f. (d) A is false but R is true 45. Assertion (A): Refractive index of glass with respect to air is different for red [1] light and violet light. Reason (R): Refractive index of a pair of media depends on the wavelength of light used. (a) Both A and R are true and R is the correct explanation of A 46. [1] Assertion (A): Kidneys purify blood. Reason (R): Renal vein has more Oxygen than renal artery. (c) A is true but R is false 12 47. Assertion (A): In plants gaseous exchange takes place by the opening and closing of Guard cells. Reason (R): The exchange of gases occurs across the surface of stem, roots [1] and Leaves. (b) Both A and R are true but R is not the correct explanation of A. 48. Assertion (A): MnO2 + 4HCl MnCl2 + Cl2 + 2H2O is a redox reaction. [1] Reason (R): MnO2 oxidizes HCl to Cl2 and gets reduced to MnCl2 (a) Both A and R are true and R is the correct explanation of A 49. Assertion (A): If the pH inside the mouth decreases below 5.5, the decay of [1] tooth enamel begins. Reason (R) : The bacteria present in the mouth degrades the sugar and left over food particles and produce acids that remains in the mouth after eating. (a) Both A and R are true and R is the correct explanation of A 50. Assertion (A): The aqueous solutions of glucose and alcohol do not show acidic character. Reason (R): Aqueous solutions of glucose and alcohol give H+ ions. (c) A is true but R is false ***** 13 [1]
|
