WBCS Preliminary Question – 2019
(A) Chlorine      Â
(B) Sulphur     Â
(C) Phosphorus      Â
(D) Silicon
Â
(CH4N2O, N content 46%)
(A) Urea    Â
(B) Ammonium Nitrate   Â
(C) Potassium Nitrate     Â
(D) Ammonium Phosphate
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(citric acid, pH 2.2)
(A) Lemon juice     Â
(B) Lime water     Â
(C) Human blood     Â
(D) Antacid
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138. To
protect tooth decay we are advised to brush our teeth regularly. The nature of the toothpaste commonly used is
(A) acidic     Â
(B) neutral     Â
(C) basic    Â
(D) corrosive
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(CaO, 60-65%)
(A) Gypsum      Â
(B) Limestone     Â
(C) Clay      Â
(D) Ash
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(metal alloy)
(A) Copper & Zinc    Â
(B) Copper & Tin     Â
(C) Copper, Nickel & Zinc    Â
(D) Copper, Aluminum & Mg
Â
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WBCS Preliminary Question – 2018
(a) increase
(b) decrease
(c) remains same
(d) None of the above
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(a) decomposition
(b) hydrolysis
(c) reduction
(d) oxidation
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(CH3COOH)
(a) Sodium nitrate
(b) Dilute acetic acid
(c) Chloride of lime
(d) Calcium
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(C2H3Cl)n
(a) Polyvinyl Chloride
(b) Polyvinyl carbonate
(c) Phosphor Vanadium Chloride
(d) Phospho Vinyl Chloride
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(a) Graphite
(b) Gypsum
(c) Zinc
(d) Lead
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WBCS Preliminary Question – 2017
(A) Lindlar catalyst
(B) H2/Pd
(C) NaBH4
(D) LiAlH4
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32. Conversion of RBr to RMgBr requires
(A) Mg /dry ether / N2 – atmosphere
(B) Mg/ moist ether /N2 – atmosphere
(C) Mg/ ethanol /N2 -atmosphere
(D) Mg / dry ether /O2 – atmosphere.
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(A) MeO — CH2 –Cl
(B) Me — CH2 -Cl
(C) Me –C –CH2 –Cl
(D) Ph — CH2 –CH2 – Cl
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(alkali metals)
(A) Cs   (Cesium)
(B) Li
(C) Mg
(D) K
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(Sulfur tetrafluoride)
(A) square planar
(B) tetrahedral
(C) octahedral
(D) see-saw
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(Gibbs free energy)
(A) Delta G = -ve
(B) Delta H = -veÂ
(C) Delta S = +ve
(D) Delta S = -ve
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(A) Copper
(B) Platinum
(C) Iron
(D) Lead
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WBCS Preliminary Question – 2016
97. Which among the following is called ‘Laughing Gas’ popularly ? (N2O)
(A) Nitric oxide      Â
(B) Nitrous oxide     Â
(C) Nitrogen penta oxide     Â
(D)Â Nitrogen
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(CH3NCO, Union Carbide India Limited)
(A) Methyl isocyanides     Â
(B) Methyl isocyanate
(C) Methyl isochloride   Â
(D) Methyl isochlorate
Â
(A) Iron       Â
(B) Zinc      Â
(C) Aluminium       Â
(D)Â Magnesium
Â
(A) Nitrogen       Â
(B) Carbon dioxide        Â
(C) Hydrogen
(D)Â Neon
Â
(Montreal Protocol in 1987)
(A) Carbon monoxide     Â
(B) Carbon dioxide     Â
(C) Chlorofluoro carbon
(D) Mercuric oxide
Â
(A) Phospho Vinyl Chloride       Â
(B) Poly Vinyl CarbonateÂ
(C) Poly Vinyl Chloride
(D) Phospho Vanadium Chloride
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WBCS Preliminary Question – 2015
(A) Ca2+
(B) Na+
(C) Zn2+
(D) Cu+
Â
Â
(A) sp  sp3
(B) sp2 sp       Â
(C) sp2Â Â sp2
(D) sp  sp
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(Hydrofluoric acid)
(A)Â HNO3
(B) HCl       Â
(C)Â HF
(D)Â HBr
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(Atomic weight : Na = 23, 0 = 16, H = l)
(A) 2
(B) 20Â Â Â Â Â Â
(C) 4Â Â Â Â Â
(D)Â 1
Â
(A) Acetyl salicylic acid
(B) Sodium salicylate     Â
(C) Methyl salicylate      Â
(D) Ethyl salicylate
Â
Â
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WBCS Preliminary Question – 2014
(A) Platinum      Â
(B) Silver     Â
(C) lron     Â
(D)Â Gold
Â
(Noble gas)
(A) Helium     Â
(B) Neon       Â
(C) Argon
(D)Â Xenon
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(Na2CO3)
(A) Sodium carbonate Â
(B) Calcium carbonate     Â
(C) Sodium bicarbonate     Â
(D) Sodium hydroxide
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167. The half-life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind ? (radioactive decay)
(A) 1/6Â Â Â Â Â Â
(B) 1/3Â Â Â Â Â Â Â
(C) 1/8
(D)Â 1/4
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(A) Zero
(B) One    Â
(C) Two    Â
(D)Â Three
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WBCS Preliminary Question – 2013
48. One of the breakthrough of Acharya P. C. Roy was to synthesize the following compound : (Ammonium nitrite, 1896)
(A) HgCl2
(B) NH4NO2 Â Â Â Â
(C) Hg2Cl2
(D) H2O4
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(Hard Water)
(A) K
(B) Ca     Â
(C) As   Â
(D)Â Fe
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(HCL, spirits of salt)
(A) Acetic acid     Â
(B) Hydrochloric acid
(C) Oxalic acid    Â
(D) Aqua regia
Â
69.  Which metal ion is associated with Haemoglobin ? (A) Mg++
(B) Fe++
(C) Al+++
(D) Mn++
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72. Phenyl used in household work is a derivative of — (Phenyl – C6H5)
(A) Methyl alcohol     Â
(B) Tartaric acid      Â
(C) Benzene   Â
(D)Â Anthracene
Â
(Dichlorodiphenyltrichloroethane)
(A) Air only   Â
(B) Air and soil only      Â
(C) Air, soil and water only
(D) Air and water only
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190. ‘Higgs Boson’ is :
(God particle)
(A) Name of a film     Â
(B) An elementary particle
(C) Generic name of a medicine  Â
(D)Â Planet
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WBCS Preliminary Question – 2012
(A) 5.20
(B) 4.80Â Â Â Â Â
(C) 5.80Â Â Â Â
(D)Â 4.85
Â
167. How many grams of dibasic acid (mol wt 200) should be present in 100 ml of its aqueous solution to give 0.1(N) strength ? (A) 2 gm     Â
(B) 1gm     Â
(C) 10 gm    Â
(D) 20Â gm
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(polyvinyl chloride)
(A) Rubber     Â
(B) Nylon 6-6Â Â Â Â Â Â Â
(C)Â PVC
(D)Â Bakelite
Â
(detecting peptide bonds)
(A) Molish’s test    Â
(B) Biuret test
(C) DNP test   Â
(D) Benedict’s test
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WBCS Preliminary Question – 2011
95. Vulcanisation is the process of heating rubber with 3 – 5% of (synthetic rubber)
(A) Sulphur
(B) Lime     Â
(C) Potassium permanganate     Â
(D)Â Naphthalene
Â
(refrigerants – CFC & HCFC)
(A) Nitrogen dioxide    Â
(B) Sulphur dioxide      Â
(C) Freon  Â
(D) Chlorine nitrate
Â
(substitutional alloy)
(A) Iron and Copper    Â
(B) Copper and Tin     Â
(C) Copper and Aluminium    Â
(D) Copper and Zinc
Â
(PAN – C2H3NO5)
(A) Peroxyacetyl nitrate
(B) Nitrogen monoxide     Â
(C) Ultra violet rays   Â
(D)Â Hydrocarbon
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Â
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WBCS Preliminary Question – 2010
(A) Uranium 238
(B) Plutonium 239Â Â Â Â Â Â
(C) Neptunium 239Â Â Â Â
(D) Thorium 236
Â
(CH4, Compressed natural gas)
(A) Petrol      Â
(B) Alcoholic fuel       Â
(C)Â CNG
(D)Â Diesel
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WBCS Preliminary Question – 2009
34. At constant temperature if the pressure decreases, then the volume of a given mass of gas will (Boyle’s law)
(A) Increase
(B) Decrease       Â
(C) Remain constant
(D) May increase or decrease depending on nature of the gas
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54. Normal saline is an aqueous solution of sodium chloride of strength (A) 0.84 %Â Â Â (0.9%)
(B) 1.00 normal
(C) 1.00 molar
(D) 1Â %
Â
(A) An allotrope of carbon
(B) A synonym for carborundum
(C) Artificial emery    Â
(D) A compound of carbo
Â
(A) Nuclear fusion    Â
(B) Spallation      Â
(C) Nuclear fission
(D) Nuclear isomerisatio
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Â
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WBCS Preliminary Question – 2008
(A) Progression
(B) Regression
(C) Sublimation
(D) Repression
Â
(A) Malic acid
(B) Formic acid
(C) Iso-citric acid
(D) Fumeric acid
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(A) Arsenic
(B) Bismuth
(C) Lead
(D) Tin
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WBCS Preliminary Question – 2007
32.
Neutron was discovered by
(1930)
(A) J. Chadwick
(B) J.J Thomson
(C) Rutherford
(D Neil Bohr
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(A) FeSO4 ,7H2O
(B) ZnSO4 ,7H2O
(C) MgSO4 ,7H2,O
(D) CuSO4 ,5H2O
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(A) Hot dil. NSO4
(B) cold dil. HNO3
(C) Fuming HNO3
(D) None of the above
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(A) 0
(B) –1/2
(C) -1
(D) +2
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(A) Good conductor of heat
(B) High density
(C) Good Conductor of electricity
(D) High coefficient of expansion
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(A) emulsion
(B) gel
(C) foam
(D) sol
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143. Which of the following substances can act as only
reducing agent?
(A) H2O2
(B) MnO2
(C) K2Cr2O2
(D) H2S
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WBCS Preliminary Question – 2006
(a) Lyman series
(b) Balmer series
(c) Brackett series
(d) Paschen series
Â
(a) H2O
(b) NOÂ Â Â (Nitric oxide)
(c) CO2
(d) SO2
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(a) Using a separating funnel
(b) Evaporation
(c) Fractional distillation
(d) Allowing the water to evaporate
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(a) HCHO
(b) CH3OHÂ Â Â Â (Methanol)
(c) CH2 = CH2
(d) CH2CHO
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WBCS Preliminary Question – 2005
57. Which one of the following is not a metal?
(a) Platinum
(b) Mercury
(c) Nickel
(d) Silicon
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101. Oxygen was discovered by
(a) Priestley
(b) Lavoisier
(c) Charles
(d) Boyle
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102. Which one of the following is in the mixture of sympathetic ink?
(a) Cobalt chloride and water
(b) Zinc chloride and water
(c) Magnesium chloride and water
(d) None of the above
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108. The process by which the gas comes out of an L.P.G. Cylinder is called
(a) Diffusion
(b) Effusion
(c) Pressure
(d) Ventilation
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119.
L.P.G. Cylinders contain inside
(a) Butane and Isobutane
(b) Butane and Propane
(c) Isobutane and Propane
(d) Butane, Isobutane and Propane
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WBCS Preliminary Question – 2004
30. When a helium atom loses an electron, it is converted to a
(A) Proton
(b) L-patical
(C) Deuteron
(D) Helium ion
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50. What is stored in a storage cell?
(A) Electric charge
(B) Electric potential
(C) Lead or some other metal
(D) Chemical energy
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102. In the solar spectrum Fraunhofer lines are seen in the sodium D wavelength This proves
(A) there is no sodium in the sun
(B) there is no sodium in the solar atmosphere
(C) there is no sodium in the sun’s interior
(D) there is sodium in the solar atmosphere
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WBCS Preliminary Question – 2003
43. Hydrogen bomb is based, on the principle of
(A) Nuclear fission
(B) Nuclear fusion
(C) Nuclear explosion
(D) None of the above
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83. If the density of air is 1.30 g/lit. what is the volume occupied by 7.8g of air?
(A) 10 lit.
(B) 6 lit.
(C) 6.5 lit.
(D) 10/10 lit
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103. The purest form of iron is
(A) Wrought iron
(B) Cast iron
(C) Iron turning
(D) Stainless steel
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123. Solar energy is due to
(A) Nuclear fusion reaction
(B) Chemical reaction
(C) Nuclear fission reaction
(D) Burning of H
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WBCS Preliminary Question – 2002
24. The unit of radioactivity is
(SI unit – Becquerel, non-SI unit – Rutherford)
(A) Plank
(B) Einstein
(C) Curie
(D) None of the above
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29. Which one of the following is an element?
(A) Table salt
(B) Water
(C) Graphite
(D) Glass
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40. The relative humidity inside a room is 50% while the temperature is 30°C. If the temperature becomes 40°C, then the relative humidity
(A) Will increase
(B) Will decrease
(C) Will remain unchanged
(D) Will increase or decrease depending upon the size of the room.
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49. Colloidal particles do not settle down because
(A)Their specific gravity is very low
(B)They are present in far smaller quantities than that of the dispersion medium
(C)they carry electrical charge
(D)The become solvated
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56. Lightning discharges in induce rain formation. This is because they cause.
(A) Nitrogen and oxygen of the air to combine
(B) Some gas molecules to ionize
(C) The electrical discharge active the H2O molecules
(D) They induce photochemical reactions.
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70. A Plant cell shrinks when placed in
(A) Water
(B) A solution isotonic with the cell sap
(C) A hypertonic solution
(D) A hypotonic solution
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141. All reactions involving chemical decomposition
(A) Are reversible
(B) Are endothermic
(C) Are reversible and endothermic
(D) May be reversible or irreversible and exothermic or endothermic
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167. Which of the following metals is the best conductor of heat and electricity?
(A) Sodium
(B) Copper
(C) Silver  (Ag)
(D) Potassium
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WBCS Preliminary Question – 2001
18. The most abundant ions in the Bay of Bengal water are
(A) Na+ and Cl–
(B) H+ and OH–
(C) Mg2+ and SO42-
(D) Fe2+ and Cl–
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21. Phosgene is a common name of
(A) phosphorus trichloride
(B) phosphorus oxychloride
(C) phosphine
(D) Carbonyl dichloride
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59. Which of the following mixtures can be separated by using a separating funnel?
(A) water + sugar
(B) water + milk
(C) water + oil
(D) petrol + kerosene
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72. A substance used in metallurgy to remove rock material is called
(A) matrix
(B) slag
(C) flux
(D) gangue
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83. Graphite is used in a nuclear reactor.
(A) as a lubricant
(B) as a fuel
(C) for lining inside the reactor as an insulator
(D) for reducing the velocity of the neutron
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106. Glass is best described as
(A) a gel
(B) an alloy
(C) a eutectic mixture
(D) a supercooled solution
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114. What are potato ores?
(A) Potato of Namital and Himachal Pradesh
(B) HYV seed potato raised in irrigated tracts of W.B.
(C) Nodules of a variety of minerals found on the sea beds
(D) Ores of nuclear minerals
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117. In the manufacture of steel by open hearth process cast iron used has no phosphorus but has manganese as an impurity. The furnace should have a lining of
(A) magnesia
(B) lime
(C) silica
(D) lime or magnesia
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118. Nuclei of radioactive elements emit
(beta particle or positron)
(A) neutrons
(B) protons
(C) either protons or neutrons
(D) neither protons nor neutrons
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121. Particles that can be added to the nucleus of an atom without changing chemical properties are called
(A) neutron
(B) proton
(C) electron
(D) αparticle
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(A) -6.8eV
(B) -3.4eV
(C) -27.2eV
(D) -13.6eV
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129. Vinegar is a dilute solution of
(A) formaldehyde
(B) formic acid
(C) ethanol
(D) acetic acid   (CH3COOH)
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179. A pair of compounds that cannot exist together in a solution is
(A) sodium bicarbonate and caustic soda
(B) sodium bicarbonate and water
(C) sodium bicarbonate and sodium carbonate
(D) sodium carbonate and caustic soda
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WBCS Preliminary Question – 2000
21. In the process of vulcanisation which two of the following are heated together?
(A) Rubber and Sulphur
(B) Latex and Sulphur
(C) Rubber and Steel
(D) Rubber and Lead
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98. Corrosion is a form of _______erosion.
(A) Mechanical
(B) Chemical
(C) Biological
(D) Biophysical
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24. When a liquid is heated from 20°C to 60°C its density
(A) Remains the same
(B) Increases
(C) Decreases
(D) Is lost
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30. Solar energy is produced by the process of
(A) Fusion
(B) Fission
(C) Explosion
(D) Contraction
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31. Which of the following are called Noble gases?
(A) Oxygen and Hydrogen
(B) Oxygen and Argon
(C) Argon and Neon
(D) Hydrogen and Neon
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33. In underground Railways air is purified by using
(A) Ozone
(B) Hydrogen peroxide
(C) Oxygen
(D) None of the above
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34. In 1775 a scientist experimentally showed that air consists of two gases. The name of the scientist is
(A) Priestley
(B) Laboisier
(C) Darwin
(D) Davy
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35. Dry ice is made up of
(A) Water
(B) Chlorine
(C) Hydrocarbon
(D) Carbon dioxide
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36. Water gas is a mixture of
(A) Carbon monoxide and Hydrogen
(B) Carbon di-oxide and Hydrogen
(C) Carbon monoxide and Nitrogen
(D) Carbon di-oxide and Nitrogen
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45. In ripening fruit which one of the following is used?
(A) Ethylene
(B) Acetylene
(C) Methane
(D) Polyvinyl chloride
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