41. The abrasive recommended for grinding materials of low tensile strength is
A. silicon carbide
B. aluminium oxide
C. sand stone
D. diamond
42. The chamfering is an operation of
A. bevelling the extreme end of a workpiece
B. embossing a diamond shaped pattern on the surface of a workpiece
C. reducing the diameter of a workpiece over a very narrow surface
D. enlarging the end of a hole cylindrically
43. The hard grade grinding wheels are denoted by the letters
A. A to H
B. I to P
C. Q to Z
D. A to P
44. The tailstock set over required to turn a taper on the entire length of a workpiece having diameters D and d is
A. D-d/2L
B. D-d/L
C. D-d/2
D. D – d
45. The angle formed by the leading edge of the land with a plane having the axis of the drill, is called
A. helix or rake angle
B. point angle
C. chisel edge angle
D. lip clearance angle
46. The lip clearance angle should decrease towards the centre of the drill than at the circumference.
A. Yes
B. No
47. If the shear angle is large and the chip-tool contact area is low, then the tool life will be more.
A. Correct
B. Incorrect
48. In drilling brass, a drill with
A. zero helix angle is used
B. low helix angle is used
C. high helix angle is used
D. any helix angle can be used
49. The carbide tools operating at very low cutting speeds (below 30 m/min)
A. reduces tool life
B. increases tool life
C. have no effect on tool life
D. spoils the work piece
50. In oblique cutting of metals, the cutting edge of the tool is
A. perpendicular to the workpiece
B. perpendicular to the direction of tool travel
C. parallel to the direction of tool travel
D. inclined at an angle less than 90° to the direction of tool travel