59) The difference between length and breadth of a rectangle is 23m. If its perimeter is 206m, then its area is,

60) Hot forging lubricants are

61) A bolt is specified as M16x1.5x100. Number 1.5 stands for

62) _____ is a drop hammer used in forging

63) A drop hammer is used to forge a steel rod. If the energy transferred is 7500 Joules and the downward force exerted by the hammer is 15 tons, the distance the hammer travelled after striking is _____ mm