65) One of the taper turning methods is by offsetting the tailstock. Which part of the tailstock is offset ?

66) Lead is the metal used for balancing weight during lathe face plate work. The reason for using lead is that it is very

67) While power feed is engaged when turning taper by using taper turning attachment, it is noticed that for short distance parallel turning takes place due to certain defect. Which one of the following is the cause for this defect ?

68) For cutting acme threads, the threading tool should be ground to an included angle of

69) To cut 20 mm internal square thread with a pitch of 2.5 mm, the core diameter should be