21. In a shaper, the metal is removed during
A. forward stroke
B. return stroke
C. both the forward and return strokes
D. neither the forward nor the return stroke
22. The aluminium oxide abrasive is chiefly used for grinding
A. high speed steel
B. carbon steel
C. wrought iron
D. all of these
23. In __________ operation, the chip thickness is minimum at the beginning of the cut and it reaches to the maximum when the cut terminates.
A. conventional milling
B. climb milling
C. face milling
D. end milling
24. In __________ operation, the cutting force is maximum when the tooth begins its cut and reduces it to minimum when the tooth leaves the work.
A. up milling
B. down milling
C. face milling
D. end milling
25. The taper on the lathe spindle is
A. 1 in 10
B. 1 in 15
C. 1 in 20
D. 1 in 30
26. Which of the following statement is correct in regard to centreless grinding?
A. The workpiece is supported throughout its entire length as grinding takes place.
B. It is a continuous process and adopted for production work.
C. It requires no holding device for the work.
D. all of the above
27. The specific cutting energy used for establishing the machinability of the metal depends upon its
A. coefficient of friction
B. microstructure
C. work hardening characteristics
D. all of these
28. The form grinding is used to grind gear teeth, threads, splined shafts and holes.
A. Correct
B. Incorrect
29. Which of the following parameters govern the value of shear angle in continuous chip formation?
A. True feed
B. Chip thickness
C. Rake angle of the cutting tool
D. all of these
30. The relief or clearance at the cutting edge of a flat drill varies from
A. 3° to 8°
B. 20° to 30°
C. 60° to 90°
D. 90° to 120°
31. In drilling bakellite and fibrous plastics, the point angle of a drill is
A. 90°
B. 118°
C. 135°
D. 150°
32. The shear velocity is the velocity of
A. tool relative to the workpiece
B. chip relative to the tool
C. tool along the tool face
D. none of these
33. In centreless grinders, the regulating wheel is inclined at
A. 0° to 8°
B. 9° to 15°
C. 16° to 20°
D. 21° to 25°
34. A grinding wheel is said to be of __________ if the abrasive grains can be easily dislodged.
A. soft grade
B. medium grade
C. hard grade
35. In drilling softer materials, the cutting speed is __________ as compared to harder materials.
A. same
B. low
C. high
36. Which of the following statement is correct about hot machining?
A. It requires less power than machining metals at room temperature.
B. The rate of tool wear is lower.
C. It is used for machining high strength and high temperature resistant materials.
D. all of the above
37. For turning internal tapers, the suitable method is
A. by a form tool
B. by setting over the tail stock
C. by a taper turning attachment
D. by swivelling the compound rest
38. Lathe bed is made of
A. mild steel
B. alloy steel
C. pig iron
D. chilled cast iron
39. In metal machining, the zone where the maximum heat is generated due to the plastic deformation of metal, is called
A. friction zone
B. work-tool contact zone
C. shear zone
D. none of these
40. The operation of making a cone-shaped enlargement of the end of a hole is known as
A. counter-sinking
B. counter-boring
C. trepanning
D. spot facing