Engineering Materials

41. Chilled cast iron has

1. no graphite
2. a very high percentage of graphite
3. a low percentage of graphite
4. graphite as its basic constituent of composition
5. none of the above is true.

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42. Chromium in steel

1. improves wear resistance, cutting ability and toughness
2. refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
3. improves cutting ability and reduces hardenability
4. gives ductility, toughness, tensile strength and anticorrosion properties
5. makes steel hard.

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43. Cobalt in steel

1. improves wear resistance, cuttinability and toughness
2. refines grain size and produces les tendency to carburisation, improve corrosion and heat resistant proper ties
3. improves cutting ability and reduce hardenability
4. gives ductility, toughness, tensile strength and anti corrosion property:
5. none of the above.

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44. Cold rolled steel sheets contain carbon of the following order

1. 0.1%
2. 0.2%
3. 0.4%
4. 0.6%
5. 0.8%.

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45. Compressive strength of grey cast iron in tonnes/cm is of the order of

1. 43954
2. 44017
3. 44111
4. 42278
5. 15-22.

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46. Connecting rod is usually made of

1. aluminium
2. low carbon steel
3. medium carbon steel
4. high carbon steel
5. cast iron.

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47. Constantant an alloy used in thermocouples is an alloy of

1. copper and tin
2. copper and zinc
3. copper and iron
4. copper and nickel
5. copper and chromium.

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48. Corrosion resistance of steel is increased by adding

1. chromium and nickel
2. nickel and molybdenum
3. aluminium and zinc
4. tungsten and sulfur
5. none of the above.

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49. Corrosion resistance of steel is increased by addition of

1. chromium and nickel
2. sulphur, phosphorus, lead
3. vanadium, aluminium
4. tungsten, molybdenum, vanadium, chromium
5. zinc.

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50. Corrundum contains more than 95%

1. steel
2. A1203
3. Si02
4. MgO
5. german silver.

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