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1) Tensile strength of steel can be safely in-creased by________________? a. adding carbon up to 2.8% b. adding carbon up to 6.3% c. adding carbon up to 0.83% d. adding small quantities of copper e. adding copper and carbon
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2) Cobalt in steel __________________? a. improves wear resistance, cuttinability and toughness b. refines grain size and produces les tendency to carburisation, improve corrosion and heat resistant proper ties c. improves cutting ability and reduce hardenability d. gives ductility, toughness, tensile strength and anti corrosion property: e. none of the above
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3) The hardness of steel increases if it contains____________________? a. austenite b. martensite c. pearlite d. cementite e. all of the above
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4) Nodular iron has____________________? a. high maehinability b. low melting point c. high tensile strength d. good fluidity e. all of the above
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5) Which of the following elements does not impart hardness to steel__________________? a. copper b. chromium c. nickel d. silicon e. none of the above
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6) Melting point of iron is__________________? a. 1539°C b. 1601°C c. 1489°C d. 1712°C e. 1131°C
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7) Blast furnace produces following by reduction of iron ore_______________? a. cast iron b. pig iron c. wrought iron d. malleable iron e. white iron
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8) The machinability of steel is increased by___________________? a. silicon and sulphur b. phosphorous, lead and sulphur c. sulphur, graphite and aluminium d. phosphorous and aluminium e. none of the above
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9) Which of the following element results in presence of free graphite in C.I_________________? a. carbon b. sulphur c. silicon d. manganese e. phosphorous
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10) Cold rolled steel sheets contain carbon of the following order___________________? a. 0.1% b. 0.2% c. 0.4% d. 0.6% e. 0.8%
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11) Large forgings, crank shafts, axles normally contain carbon up to________________? a. 0.05 to 0.20% b. 0.20 to 0.45% c. 0.45 to 0.55% d. 0.55 to 1.0% e. 1.0 to 1.2%.
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12) Taps, dies and drills contain carbon________________? a. below 0.5% b. below 1% c. above 1% d. above 2.2% e. nil
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13) Which is the false statement about wrought iron. It has________________? a. high resistance to rusting and corrosion b. high ductility c. ability of hold protective coating d. easily weldable characteristics e. uniform strength in all directions
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14) Balls for ball bearings are made of_________________? a. cast iron b. mild steel c. stainless steel d. carbon-chrome steel e. high carbon steel
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15) Preheating is essential in welding ___________________? a. cast iron b. high speed steel c. all non-ferrous materials d. all of the above e. none of the above
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16) The tensile strength of wrought iron is maximum _________________? a. along the lines of slag distribution b. perpendicular to lines of slag distribution c. uniform in all directions d. unpredictable e. none of the above
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17) Drop forging dies contain carbon of the order of_________________? a. 0.1 to 0.2% b. 0.25 to 0.5% c. 0.6 to 0.7% d. 0.7 to 0.9% e. 1.0 to 1.2%.
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18) Heavy duty leaf and coil spring* contain carbon of the following order ________________? a. 0.2% b. 0.5% c. 0.8% d. 1.0% e. 1.5%.
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19) Pipes for bicycle frames are made of___________________? a. cold rolled steel b. hot rolled steel c. forged steel d. cast steel e. carbon-chrome steel
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20) White cast iron__________________? a. contains 1.7 to 3.5% carbon in free state and is obtained by the slow cooling of molten cast iron b. is also known as chilled cast iron and is obtained by cooling rapidly. It is almost unmachinable c. is produced by annealing process. It is soft, tough and easily machined metal d. is produced by small additions of magnesium (or creium) in the ladle. Graphite is in nodular or spheroidal form and is well dispersed throughout the m e. none of the above
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