Manufacturing Engineering Multiple Choice Questions on “Deep Drawing”.
1. In which of the following process the work piece is pulled through a die resulting in reduction of area?
a) Forging
b) Drawing
c) Forming
d) Extrusion
Answer: b
Clarification: Large quantities of wires, rods, tubes and other sections are produced by drawing process which is basically a cold working process. In this process, the material is pulled through a die in order to reduce it to the desired shape and size. In a typical wire drawing operation, one end of the wire is reduced and passed through the opening of the die, gripped and pulled to reduce its diameter.
2. In drawing which angle allows the introduction of lubricant into the working zone?
a) Entrance angle
b) Die angle
c) Semi-die angle
d) Relief angle
Answer: a
Clarification: The entrance angle provides the entry zone to allow the introduction of lubricant into the working zone and to protect the work material against scoring by die edges. The angle is usually about 40°.
3. Degree of drawing is measured in terms of?
a) Reduction in stress
b) Reduction in force
c) Reduction in area
d) Reduction in strain
Answer: c
Clarification: The degree of drawing is measured in terms of “reduction of area” which is defined as the ratio of the difference cross-sectional area before and after drawing to the initial cross-sectional area.
4. The maximum reduction in cross sectional area per pass is?
a) 45%
b) 63%
c) 55%
d) 67%
Answer: b
Clarification: For perfectly plastic material, the ideal maximum reduction per pass is 63%. For a strain hardening material, the ideal maximum reduction per pass depends on the strain hardening coefficient. For example, for n = 0.19, then the maximum reduction per pass is 69.5%.
5. Which of the following die is used in drawing flat strips?
a) Square shaped
b) Rectangular shaped
c) Circular shaped
d) Wedge shaped
Answer: d
Clarification: Wedge shaped die is used in drawing flat strips.
6. As the reduction increases, drawing force must be?
a) Decreases
b) Increases
c) Does not change
d) First increases and then decreases
Answer: b
Clarification: With the increase in reduction the drawing force increases.
7. Which of the following angle influence the drawing force and the quality of drawn products?
a) Entrance angle
b) Die angle
c) Relief angle
d) Flake angle
Answer: b
Clarification: Die angle influence the drawing force and the quality of drawn products. Die angle should be kept appropriate for better surface finish.
8. Degree of drawing is given by the expression?
a) (di-df)
b) (Ai-Af)
c) (Ai-Af)/Ai
d) 1-((df-di))
Answer: c
Clarification: Degree of drawing is given by the expression(Ai-Af)/Ai. Where d is the diameter of tube.
9. If the initial diameter is 50mm2 and the final diameter after drawing is 40mm2, then the degree of drawing is?
a) .64
b) .20
c) .80
d) .36
Answer: d
Clarification: Degree of drawing is given by [1- (df/di)2]. Where d is the diameter of tube.
10. If the degree of drawing is 0.5 and the initial area is 100mm2 then the final area in mm2 is equal to?
a) 50
b) 60
c) 40
d) 30
Answer: a
Clarification: Degree of drawing= (Ai-Af)/Ai. Where d is the diameter of tube, A is area.