64) The process of increasing the diameter of a ring by forging is called

65) The accuracy of micrometer and caliper are checked by

66) Ram drives his car at a speed of 50 km/hr for 6 hours and 37.5 km/hr for next 4 hours. What is his average speed?

67) Edge angle of a cold chisel is

68) _____ is used for measuring temperature inside a furnace