Description : In mirrors the back surface is coated with a thin layer of (1) Mercury (2) Silver (3) Red oxide (4) Silver nitrate
Last Answer : (2) Silver Explanation: In a spherical mirror, one of the two curved surfaces is coated with a thin layer of silver followed by a coating of red lead oxide paint. Thus, one side of the spherical minor is opaque and the other side is a highly polished reflecting surface.
Description : A 'breath test' used by traffic police to check drunken driving uses: (1) potassium dichromate-sulphuric acid (2) potassium permanganate-sulphuric acid (3) turmeric on filter paper (4) silica gel coated with silver nitrate
Last Answer : (1) potassium dichromatesulphuric acid Explanation: The main constituent of alcohol is Ethanol and the concentration of ethanol in a sample can be determined by back titration with acidified potassium ... contact with the yellow dichromate-coated crystals, the color changes from yellow to green.
Description : Photographic plates are coated with (A) Silver nitrate (B) Silver halide (C) Calcium silicate (D) Metallic silver
Last Answer : (B) Silver halide
Description : A ‘breath test’ used by traffic police to check drunken driving uses: (1) potassium dichromate-sulphuric acid (2) potassium perma-nganatesulphuric acid (3) turmeric on filter paper (4) silica gel coated with silver nitrate
Last Answer : potassium dichromate-sulphuric acid
Description : Which of the following is coated as a thin layer on the inner side of non-stick pans?
Last Answer : Which of the following is coated as a thin layer on the inner side of non-stick pans? A. Bakelite B. PVC C. Teflon D. Polypropylene
Description : A soil mass coated with a thin layer of paraffin weighs 460 g. When immersed, it displaces 299 cc of water. The weight of paraffin is 10 g. If specific gravity of solids is 2.5 and that of paraffin 0.9, the void ratio of soil, is (A) 0.55 (B) 0.60 (C) 0.65 (D) 0.70
Last Answer : Answer: Option B
Description : Hard disk is coated in both side with A) Magnetic metallic oxide B) Optical metallic oxide C) Carbon layer D) All of the above
Last Answer : Answer : A
Description : Hard disk is coated in both sides with A) Magnetic metallic oxide B) Optical metallic oxide C) Carbon layer D) All of the above
Description : Hard disk is coated in both side above a. Magnetic metallic oxide b. Optical metallic oxide c. Carbon layer d. All of the above
Last Answer : Magnetic metallic oxide
Last Answer : a. Magnetic metallic oxide
Description : On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because (1) Mercury is a metal (2) Density of mercury is greater than that ... is greater than its adhesion with glass (4) Cohesion of water is greater than its adhesion with glass
Last Answer : (3) Cohesion of mercury is greater than its adhesion with glass Explanation: When liquid is placed on a smooth surface like glass plate, the relative strengths of the cohesive and adhesive forces acting on ... and a surface are stronger, they will pull the liquid down, causing it to wet the surface.
Last Answer : Cohesion of mercury is greater than its adhesion with glass
Description : What among following is used to produce artificial rain? (1) Copper oxide (2) carbon monoxide (3) silver iodide (4) silver nitrate
Last Answer : (3) silver iodide Explanation: Artificial process of making rain is done by precipitation, a process of condensation of water vapors in the air. This is done by using cloud seeding chemicals like potassium iodide, silver iodide, liquid propane or solid carbon dioxide (dry ice).
Description : What among following is used to produce artificial rain? (1) copper oxide (2) carbon monoxide (3) silver iodide (4) silver nitrate
Last Answer : (3) silver iodide Explanation: Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride.
Description : What happens when? a) A cleaned iron plate or iron nail is kept in 10g of copper sulphate solution. b) A pinch of mercuric oxide is kept in a test tube. c)A small crystal of silver nitrate is dissolved in distilled water and a drop of ammonium hydroxide & a pinch of glucose powder are added.
Last Answer : a) A cleaned iron plate or iron nail is kept in 10g of copper sulphate solution. After a few hours a coating of copper is seen on iron nail/plate. It is based on displacement reaction. ... on the inner walls of the test tube. Aldehyde group in glucose reduced silver nitrate to metallic silver.
Description : On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because (a) Mercury is a metal (b) The density of mercury is greater ... is greater than its adhesion with glass (d) The cohesion of water is greater than its adhesion with glass
Last Answer : Ans:(c)
Description : Ammonium nitrate (a fertiliser) is coated with limestone powder to (A) Increase its nitrogen content (B) Cut down its production cost (C) Avoid the risk of explosion (D) Add extra nutrient as fertiliser
Last Answer : (C) Avoid the risk of explosion
Description : The outside of the steel can is protected from rust by a thin layer of ____. a. tin c. aluminum b. copper d. silver
Last Answer : a. tin
Description : Which metal is protected by the layer of its own oxide? (A) Iron (B) Silver (C) Calcium (D) Aluminium
Last Answer : (D) Aluminium
Description : Which statement is valid about magnetic tape? A) It is a plastic ribbon B) It is coated on both sides with iron oxide C) It can be erased and reused D) All of above
Last Answer : Answer : D
Description : The substance coated on plastic tape recorder tapes is (a) zinc oxide (b) magnesium oxide (c) iron sulphate (d) iron oxide
Last Answer : Ans:(d)
Description : Which statement is valid about magnetic tape? a. It is a plastic ribbon b. It is coated on both sides with iron oxide c. It can be erased and reused d. All of above
Last Answer : It is a plastic ribbon
Last Answer : a. It is a plastic ribbon
Description : A metal is exposed to the atmosphere for some time. It becomes coated with green carbonate. The metal must be – (1) silver (2) copper (3) aluminium (4) zinc
Last Answer : (2) copper Explanation: Copper forms a rich variety of compounds with oxidation states +1 and +2, which are often called cuprous and cupric, respectively. It does not react with water, but it ... contrast to the oxidation of iron by wet air, this oxide layer stops the further, bulk corrosion.
Description : For transformation, micro-particles coated with DNA to be bombarded with gene gun are made up of (a) silver or platinum (b) platinum or zinc (c) silicon or platinum (d) gold or tungsten.
Last Answer : (d) gold or tungsten.
Description : For transfomation, micro-particles coated with DNA to be bombarded with gene gun are made up of (1) Gold or Tungsten (2) Silver or Platinum (3) Platinum or Zinc (4) Silicon or Platinum
Last Answer : (1) Gold or Tungsten
Description : A metal is exposed to the atmosphere for sometime. It becomes coated with green carbonate. The metal must be (1) silver (2) copper (3) aluminium(4) zinc
Last Answer : copper
Description : Which of the following statements concerning the maintenance of solid-silver contacts in relays and auxiliary control circuits is correct? A. When necessary, they should always be dressed with a ... they should be held together with moderate pressure while emery paper is drawn between the contacts.
Last Answer : Answer: B
Description : Which of the following materials does not form adherent oxide film on surface? (A) Copper (B) Nickel (C) Aluminium (D) Gold & silver
Last Answer : (D) Gold & silver
Description : In order to prevent the corrosion of iron pipes they are often coated with a layer of zinc. This process is termed as: A. Electroplating B. Annealing C. Galvanization D. Vulcanization
Last Answer : ANSWER: C
Description : In order to prevent the corrosion of iron pipes, they are often coated with a layer of zinc. This process is termed as (a) electroplating (b) annealing (c) galvanization (d) vulcanization
Description : Which of the following statements best describes the material known as varnished cambric? A. Felted asbestos sealed with varnish. B. Cotton cloth coated with insulating varnish. C. Rubber ... Paper impregnated with mineral oil, specially wrapped with nonmetallic tape, and coated with varnish.
Description : In order to prevent the corrosion of iron pipes they are often coated with a layer of zinc. This process is termed as------? A. Electroplating B. Annealing C. Galvanization (Answer) D. Vulcanization
Last Answer : C. Galvanization (Answer)
Description : Deep ponds, in which oxygen is absent except, perhaps, across a relatively thin surface layer, are called : (a) Aerobic ponds (b) Anaerobic ponds (c) Facultative ponds (d) Polishing ponds
Last Answer : (b) Anaerobic ponds
Description : The method of protecting iron from rusting, by coating a thin layer of Zinc is called - (1) Galvanizing (2) rancidity (3) Alloy (4) Pulverizing
Last Answer : (1) Galvanizing Explanation: Galvanisation or galvanization (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting.
Description : Why two thin shirts can keep us warmer than a single thick shirt in winter ? (1) Two thin shirts become thicker so prevent transmission of heat (2) Air layer between two shirts works as good conductor (3) Air layer between two shirts behaves like insulating media (4) No radiation of heat takes place
Last Answer : Air layer between two shirts behaves like insulating media
Description : Ozone layer above the surface of Earth provides a shield against – (1) X-rays (2) Ultra-violet rays (3) Gamma rays (4) Infra-red rays
Last Answer : (2) Ultra-violet rays Explanation: The Ozone layer absorbs 97-99% of the Sun's medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth.
Description : Ozone layer above the surface of Earth provides a shield against (1) X-rays (2) Ultra-violet rays (3) Gamma rays (4) Infra-red rays
Last Answer : Ultra-violet rays
Description : Aluminium surface are often ‘anodized’. This means deposition of a layer of which oxide?
Last Answer : Zinc oxide
Description : Oxide layer formed on the non-ferrous metal surface after its annealing is (A) Removed by acid pickling (B) Hammered into the surface (C) Removed with coarse emery cloth
Last Answer : Option A
Description : Philosopher’s wool contains zinc as its (a) oxide (b) bromide (c) nitrate (d) sulphide
Last Answer : Ans:(a)
Description : A powerful eye irritant present in smog is - (a) ozone (b) nitric oxide (c) peroxyacetyl nitrate (d) sulphur dioxide
Description : Which compound is formed when a Magnesium ribbon is burnt in air? (1) Magnesium Nitrate (2) Magnesium Carbonate (3) Magnesium Oxide (4) Magnesium Nitride
Last Answer : (3) Magnesium Oxide Explanation: When Magnesium burns air it reacts with oxygen present in air to form magnesium oxide.
Description : A powerful eye irritant present in smog is – (1) nitric oxide (2) sulphur dioxide (3) peroxyacetyl nitrate (4) carbon dioxide
Last Answer : (3) peroxyacetyl nitrate Explanation: Peroxyacetyl nitrate is a secondary pollutant present in photochemical smog. It is thermally unstable and decomposes into peroxyethanoyl radicals and nitrogen dioxide gas. It is a lachrymatory substance.
Description : Nitrogen in water is commonly found in the form of - (1) Nitrous oxide (2) Nitrate (3) Nitric oxide (4) Nitrite
Last Answer : (2) Nitrate Explanation: Nitrate (NO3) is the most common form of inorganic nitrogen in unpolluted waters. Nitrate moves readily through soils and into ground water, where concentrations can be much higher than in surface waters. Water in coastal areas mainly contains elementary nitrogen gas (N2).
Description : The chemical name of rat poison is - (1) zinc oxide (2) potassium cyanide (3) lead nitrate (4) zinc phosphide
Last Answer : (4) zinc phosphide Explanation: Zinc phosphide is used as a rodenticide. A mixture of food and zinc phosphide is left where the rodents can eat it. The acid in the digestive system of the rodent reacts with the phosphide to generate the toxic phosphine gas.
Description : Write the molecular formulae of: 1. Copper oxide 2. Iron (III) chloride 3. Sodium hydroxide 4. Iron (II) sulphide 5. Lead (II) oxide 6. Hydrogen nitrate (nitric ... Hydrogen sulphate (sulphuric acid) 8. Calcium hydroxide 9. Magnesium carbonate 10.Ammonium carbonate
Last Answer : 1. Copper oxide - CuO 2. Iron (III) chloride - FeCl3 3. Sodium hydroxide - NaOH 4. Iron (II) sulphide - FeS 5. Lead (II) oxide - PbO 6. Hydrogen nitrate (nitric acid) - HNO3 7. ... ) - H2SO4 8. Calcium hydroxide - Ca(OH)2 9. Magnesium carbonate - MgCO3 10.Ammonium carbonate - (NH4)2CO3
Description : Urea (a nitrogenous fertiliser) is produced from carbon dioxide and (A) Nitric acid (B) Ammonia (C) Ammonium nitrate (D) Nitric oxide
Last Answer : (B) Ammonia
Description : Which of the following nitrogen-containing compounds is most readily used by plants? w) nitrogen dioxide x) ammonia y) nitrous oxide z) nitrate
Last Answer : ANSWER: Z -- NITRATE