60) In which of the following resistance welding, a large number of welds can be carried out simultaneously

61) The nozzle portion of the torch employed for GTAW is made of

62) The following welding process has greater directional stability due to passage of arc through copper orifice

63) Carbon supplied by carburising flame makes the weld

64) Welding in horizontal, vertical and overhead position is difficult because the molten metal is deposited against gravity. Which physical property of metal helps in retaining the molten metal on the joint in overhead position?