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PRODUCTION TECHNOLOGEY 1. Joggled welding joints are used where severe loading

PRODUCTION TECHNOLOGEY 1. Joggled welding joints are used where severe loading is encountered and the upper surface of both pieces must be in the same plane. 2. In an arc welding, eye need to be protected against infra-red and ultraviolet rays. 3. In electro slag welding a pool of molten metal is used. 4. Plain and butt welds be used on materials upto approximately 25mm thick. 5. The main criterion for selection of electrode diameter in arc welding is the thickness of material. 6. DC is preferred for welding of non-ferrous metals by arc welding. 7. in arc welding arc is created between the electrode and work by contact resistance. 8. Open circuit voltage for arc welding is of the order of 40 to 95 volts. 9. The material used for coating the electrode is called slag. 10. Plug weld joint is used to join two pieces of metal in the same manner as rivet joint metals. 11. TIG welding process uses non consumable electrode. 12. When welding is going on, arc voltage is of the order of 18 to 40 volts. 13. Argon and Helium gases are used in tungsten inert gas welding. 14. T- joint weld is used where longitudinal shear is present. 15. In MIG welding – flux is required. 16. Copper is very difficult to be spot welded. 17. It is not possible to arc weld all types of metals with transformer set because it does not have provision for change of polarity. 18. Two sheets of same material but different thickness can be butt welded by changing the size of one electrode. 19. Projection welding is multi-spot welding process. 20. Welding processes in which two pieces to be joined are overlapped and placed between two electrodes id known as spot welding. 21. In resistance welding, voltage used for heating is 10 volts. 22. Best reason to decide use of welding in preference to riveting for structural work on extension to a hospital could be it is quieter. 23. In residence welding, the pressure is released after the weld cools. 24. Grey cast iron is best welded by oxy-acetylene. 25. Seam welding is continuous spot welding process. 26. Up to 4mm thickness of plates, edge preparation is not required. 27. Preheating is essential in welding cast iron. 28. Grey cast iron is usually welded by gas welding. 29. For welding mild steel AC, Straight polarity welding is most suitable. 30. The brazing metals and alloys commonly used are copper, copper alloys, silver alloys, aluminium alloys extra. 31. Forge welding is best suited for wrought iron. 32. Two sheets of different materials but same thickness can be spot welded by changing the size of one electrode. 33. Laser welding finds widest application in electronic industry. 34. 0.15 percentage carbon steels is most weldable. 35. Any type of configuration can be welded in friction welding. 36. Unlike materials as well as materials of different thickness can be butt welded by control of pressure and current. 37. Cross-wire welding is used in form mesh. 38. In arc welding, temperature of 5500 Degree Celsius may be generated. 39. Long arc lengths in welding would require the high voltages and low currents respectively. 40. Fluxes are used in welding in order to protect the molten metal and the surfaces to be jointed from oxidisation. 41. Metal deposited on to the work piece from the electrode is forces across the arc. 42. In arc welding operations the current value is decided by the size of the electrode. 43. The phenomenon of weld decay occurs in stainless steel. 44. Weaving of arc welding refers to side to side motion of electrode at right angles to the direction of the welding. 45. Weld spalter is welding defect. 46. Arc blowing occurs in arc welding when straight polarity is used. 47. Low hydrogen electrode are baked prior to use in order that welding is free from moisture pick up. 48. Grey iron is usually welded by gas welding. 49. Stud and projection welding belongs to the resistance welding category of welding. 50. In straight polarity welding electrode holder is connected to the negative and work to the positive. 51. In arc welding processes the intense heat is developed between the work and the electrode largely due to contact resistance. 52. In thermit welding, the iron oxide and aluminium oxide are mixed in the proportion of 3 is to 1. 53. TIG welding is best suited for welding aluminium. 54. In orthogonal cutting of metals, the cutting edge of the tools is perpendicular to the direction of tools travel. 55. In oblique cutting of metals, the cutting edge of the tool is inclined at an angle less than 90 degree of the direction of tool travel. 56. Discontinuous chips are formed during machining of brittle metals. 57. The ductile materials, during machining, produce continuous chip or continuous chips with built up edges. 58. Continuous chips with built-up edges are formed during machining of ductile metals. 59. uploads/Management/ guide 87 .pdf