Wednesday 30 July 2014

Most Important Science Questions for CBSE / NCERT / BSER / RBSE / Rajasthan Board Class 10 (Ten)



(One word/sentence Answers)

Science And Technology

Std : 10                                                                                               Max. Marks : 100

Very Short Answer Type Questions - 1 Mark                                                                 100 * 1 = 100

1. Steel is manufactured from pig iron in a Bessemer converter.
 2. What were the limitations of Dobereiner's classification?
 3. Name the two parts of vascular system in plants.
 4. Why are soaps not effective cleansing agents in hard water?
 5. What was the drawback of the law of octaves?
 6. No force acts on a current carrying conductor when it is________to the magnetic field
 7. Which was the most common source of heat energy in ancient times ?
 8. The gland X secretes a hormone Y. The deficiency of hormone Y in the body makes a person dwarf whereas the excess of hormone Y makes a person giant. Name X and Y.
 9. The changing of one form of energy into an­other form of energy is called_________ of energy.
 10. Name one natural and one man-made ecosystem.
 11. Blood has a pH in the range of __  and slightly_.
 12. What were the criteria used by Mendeleev in creating his periodic table?
 13. kWh is the unit of_______
 14. Name the two parts of central nervous system.
 15. Name the process by which many unicellular organisms remove their wastes into surrounding water.
 16. Fill in the following blank with a suitable word :
A.............in a circuit prevents damage to the appliances and the circuit due to overloading.
 17. The energy produced in a nuclear fusion reac­tion is much more than that produced during fission.
 18. Name the scientist who said that life originated from inanimate matter.
 19. State whether the following statement is true or false :
All the compounds containing hydrogen are acidic
 20. Name the uniform source of energy used by all living organisms.
 21. What is an amalgam ?
 22. What name is given to the device which automatically cuts off the electricity supply during short circuiting in domestic wiring ?
 23. Name the fuel used in an atomic power plant.
 24. When does the maturation of eggs begin in human female?
 25. Bryophyllum can be propagated vegetatively through __________ cuttings.
 26. Can steel be used for making electromag­nets?
 27. What do the ovules become after fertilisation?
 28. Name the bio molecules, which serve as internal energy reserves in (a) animals and (b) plants.
 29. Name two metals whose melting points are so low that they melt when held in the hand.
 30. An element X forms an oxide XO2 which is acidic in nature. State whether element X is a metal or a non-metal.
 31. Who are the nature and wildlife enthusiasts?
 32. Write word equation and then balanced chemical equation for the reaction taking   place when dilute sulphuric acid reacts with aluminium powder
 33. Interbreeding among individuals of different populations of a species maintains a free flow of genes in these populations.
 34. Can we change the polarity of a permanent magnet?
 35. Where are sperms deposited during sexual intercourse?
 36. In a solution of lead nitrate, a strip of metal 'M' was dipped. After some time, lead from the solution was deposited on the metal strip. Which metal is more reactive, M or lead?
 37. Name a technique used for producing disease-free plants in large numbers.
 38. Which is the major constituent of biogas ?
 39. Magnesium is more metallic in nature than sodium.
 40. Elements with eight electrons in their outermost energy shell are called_____.
 41. Chlorophyll is the pigment, which is essential for harvesting light energy.
 42. What is the source of energy of the sun and other stars.
 43. How was the rock salt formed ?
 44. Give one important way of trapping heat inside the solar cooker?
 45. By considering their position in the periodic table, which one of the following elements would you expect to have the most metallic characteristics?
Ga,Ge,As,Se,Be
 46. What is the name of:
(a) male part of a flower?     (b) female part of a flower?
 47. When is the force experienced by a current-carrying conductor placed in a magnetic field the maximum ?
 48. In which type of reaction gain of electron(s) takes place?
 49. What are villi?
 50. Which element has twice as many electrons in its second shell as in its first shell ?
 51. What is the name of tiny projections on the inner surface of small intestine which helps in absorbing the digested food.
 52. What is ductility ?
 53. (a) What are the short fibres of a neuron known as ?
(b) What is the longest fibre of a neuron known as ?
 54. Leishmamia reproduces by binary fission along a specific __________
 55. Does moving water possess energy?
 56. Apart from the availability of forest produce, name some other things which are affected by the destruction of forests.
 57. What is a thermal decomposition reaction?
 58. How do plants get rid of excess water?
 59. What are the abiotic components of ecosystem?
 60. Aluminium is the most abundant metal in the Earth's crust.
 61. What is the location of kidneys in our body?
 62. The iron ore is mixed with coke and limestone to form a mixture. This mixture is known as______.
 63. What is the other name of high blood pressure?
 64. Name any two cellular processes in which energy of ATP is utilised.
 65. Name two metals which are found in nature in free state (or native form).
 66. In the electrolytic refining of metal M, name the anode, cathode and the electrolyte.
 67. Carbon  can  form only straight chain compounds.
 68. Name an allotrope of carbon other than diamond and graphite.
 69. What would happen if all the hydrogen present in the sun is converted into helium?
 70. Identify the oxidising agent in the following reactions:
(i) 2H2 (g) + O2 (g)      2H2O (I)
(ii) CuO (s) + H2 (g) →   Cu (s) + H2O (I)
 71. Name the two best ductile metals.
 72. Name the reducing agent used to extract manganese from manganese dioxide.
 73. Iodine is necessary for adrenal gland to produce adrenaline.
 74. The action of heat on zinc carbonate to give zinc oxide and carbon dioxide is an example of a combination reaction.
75. Out of photosynthesis and respiration in plants, which process occurs :
(i) all the time?
(ii) only at day time?
76. When caustic soda reacts with zinc metal, ____ gas is evolved.
77. What name is given to those oxides which show acidic as well as basic behaviour ?
78. What do you mean by ocean thermal energy?
79. Where do the impurities go during the elec­trolytic refining of metals?
80. What was the earliest attempt to classify elements?
81. Name the functional group present in CH3 - CH=CH2
82. The molecular formula of an organic compound is C18H36.  Name its homologous series.
83. Name the instrument used to measure blood pressure?
84. What is rust? Write its chemical formula.
85. Which element has a total of three shells, with four electrons in its valence shell ?
86. How is the child born?
87. State Newland's law of octaves.
88. How does diaphragm help in inspiration?
89. Reflex action is a sudden, ………… response to a stimulus.
90. Give two important properties of baking soda
91. Name one hormone secreted by the pituitary gland.
92. Where in India washing soda is found?
93. Name the enzyme present in human saliva. What is the function of the enzyme? (or What is the role of saliva in the digestion of food ?)
94. Name the form of energy that man has been using over the ages. How does he get this energy?
95. State one disadvantage of synthetic deter­gents over soaps.
96. State whether the following statement is true or false : A wire with a green insulation is usually the live wire.
97. The atomic size in a period____.
98. Why are the green plants called producers?
99. Name the respiratory pigment present in human blood.
100. What property do all elements in the same column of periodic table as fluorine have in common ?


                ANSWERS

1. T
2. Dobereiner's failed to arrange all the then known elements in the form of triads.
3. Xylem and phloem.
4. Hard water contains metals ion such as Ca 2+ and Mg2+. Soap forms precipitate with these ions and is thus, thrown out of solution.
2RCOO-Na+ +              Mg 2+                               (RCOO)2Mg +2Na+
soap                   or Ca2+ (from hard water)               or (RCOO)2 Ca (curdy ppt.)
5. Law of octaves failed to assign the position to the elements with large atomic weights.
6. parallel.
7. Wood.
8. X is pituitary gland; Y is growth hormone
9. transformation
10. Examples of ecosystem are:
(a) Man-made - aquarium
(b) Natural - forest.
11. 7.2-7.4, basic
12. The criteria used by Mendeleev in creating his periodic table was atomic masses.
13. energy
14. Brain and spinal cord
15. Diffusion.
16. A fuse in a circuit prevents damage to the appliances and the circuit due to overloading.
17. T
18. J.B.S. Haldane.
19. False
20. ATP.
21. An alloy of mercury metal with one or more other metals is known as an amalgam.
22. Electric fuse.
23. Uranium-235.
24. Maturation of eggs in the human female begins at the onset of puberty.
25. leaf
26. No.
27. Seeds.
28. (a) Animals-glycogen, (b) Plants-starch.
29. Gallium and Cesium.
30. Non-metal.
31. The nature and wildlife enthusiasts are the people who are in no way dependent on the forests but have considerable say in their management. They try to preserve biodiversity as a whole.
32. Aluminium +   Sulphuric acid ®   Aluminium sulphate     + Hydrogen
         2A1 +       3H2SO4       ®    A12(SO4)3                + 3H2
33. T.
34. No.
35. Vagina.
36. Metal 'M' is more reactive than lead as M has displaced lead from its salt solution.
37. Tissue culture.
38. The major constituent of biogas is methane. Biogas contains upto 75 per cent of Methane
39. F
40. Noble gases
41. T
42. The source of energy of the sun and other stars are the nuclear fusion reactions (in which hydrogen nuclei fuse into helium nucleus).
43. Rock salt was formed when seas of bygone ages dried up.
44. By covering the solar cooker with a glass sheet to bring about green house effect.
45. Ga.
46. (a) Male part of a flower : Stamen
(b) Female part of a flower : Carpel
47. The maximum force is exerted on a current-carrying conductor only when it is perpendicular (at right angles) to the direction of the magnetic field.
48. The gain of electron(s) is called reduction.
49. Villi are fingerlike projections in the inner lining of intestine to increase the surface area for absorption of digested food.
50. Carbon (2, 4)
51. Villi.
52. The ability of metals to be drawn into thin wires on stretching is called ductility.
53. (a) Dendrites.
(b) Axon.
54. orientation
55. Yes
56. The destruction of forests also affects (i) quality of soil (ii) sources of water, and (iii) natural habitat of wild animals and birds.
57. The reactions in which the substances decompose on heating are called thermal decomposition reaction. For example,
CaCO3 (s)        CaO (s) + CO2 (g)
58. The plants get rid of excess water by transpiration.
59. Abiotic components of ecosystem comprise of non-living physical factors like temperature, rainfall, wind, soil and minerals and organic substances.
60. T
61. Kidneys are located in the abdomen, one on each side of the backbone.
62. charge
63. Hypertension.
64. Cellular processes like muscle contraction, conduction of nerve impulses and metabolic reactions.
65. Gold and Platinum.
66. Anode: Impure metal M
Cathode: Pure metal M
Electrolyte: Metal (M) sulphate solution
67. F
68. Buckminsterfullerene.
69. In case all the hydrogen present in the sun is converted into helium, the temperature and pressure inside the sun will decrease. As a result of this, the sun will collapse due to its own gravity. When the size of sun decreases, its interior temperature will again rise and hy­drogen nuclei will get liberated from the he­lium nuclei.
70. (i) 2H2 (g) + O2 (g) → 2H2O (I)
Oxidising agent = O2 (g)
(ii) CuO (s) + H2 (g) → Cu (s) + H2O (I)
Oxidising agent = CuO (s)
71. The two best ductile metals are
1. Silver 2. Gold
72. Aluminium.
73. F
74. F
75. (i) Respiration occurs all the time.
(ii)Photosynthesis occurs only at day time.
76. hydrogen
77. Amphoteric oxides.
78. The energy available due to the difference in temperature of water at the surface of the ocean and at deeper levels is called ocean thermal energy.
79. Impurities are collected at the bottom of anode called anode mud.
80. One of the earliest attempts was to classify the elements as metals and non-metals.
81. Alkene group.
82. Alkene series.
83. Sphygmomanometer.
84. Rust is a brown, flaky substance. Its chemical formula is Fe2O3.xH2O.
85. Silicon (2, 8, 4)
86. The child is born as a result of rhythmic contractions of the muscles in the uterus.
87. Newland's law of octaves states that "When the elements are arranged in order of increasing atomic weights, then every eighth element has properties similar to that of the first element."
88. Contraction of diaphragm muscles cause flattening of diaphragm. This increases volume of chest cavity, which creates low pressure around the lungs. As a result air is sucked into the lungs causing expansion of alveoli.
89. automatic
90. (i) On heating, it evolves CO2 gas.
(ii) It is sparingly soluble in water, giving a solution which is alkaline in nature
91. Growth hormone.
92. In India, it is found in Dehradun, Mathura, Jaunpur, Varanasi in the form of 'reh' and 'sajji'
93. Saliva contains an enzyme called 'salivary amylase'. It breaks down the complex starch carbohydrate present in food to give sugar.
94. Muscle energy by eating food.
95. Detergents are not 100 percent biodegradable, therefore, cause water pollution.
96. False.
97. Decreases
98. Green plants are called producers because they convert the solar energy into chemical energy during photosynthesis, (they produce their organic food from inorganic compounds).
99. Hemoglobin.
100. Fluorine has valency of 1 so all the elements of the same column (same group) as fluorine also have valency of 1.