Advanced Machining Processes Multiple Choice Questions on “USM – Dimensional Accuracy and Surface Quality”.
1. Which of the following distribution factors, does not affect the machining parts?
a) Side wear of tool
b) Abrasive wear
c) Accurate feed
d) Form error of tool
Answer: c
Clarification: Inaccurate feed is the factor that affects the accuracy of machining parts.
2. Which one of the following factors affects the accuracy of parts?
a) Steady abrasive flow
b) Accurate feed
c) Unsteady abrasive flow
d) Ultrasonic frequency
Answer: c
Clarification: Unsteady and uneven abrasive flow affects the dimensional accuracy.
3. State whether the statement is true or false.
“Hole oversize measures the difference between hole diameter measured at the bottom surface, and the tool diameter.”
a) True
b) False
Answer: b
Clarification: Oversize measures the difference of the hole diameter measured at top surface.
4. While machining W4C and glass, tool over cut size when compared to mean grain size is?
a) Two times greater
b) Two times smaller
c) Three times greater
d) Three times smaller
Answer: a
Clarification: Tool over cut size is 2 or 4 times greater than mean grain size.
5. While machining B4C, tool over cut size when compared to mean grain size is?
a) Two times greater
b) Two times smaller
c) Three times greater
d) Three times smaller
Answer: c
Clarification: Tool over cut is 3 times greater than mean grain size while machining B4C.
6. In the following USM accuracy levels are limited to which value?
a) ± 0.01 mm
b) ± 0.05 mm
c) ± 0.10 mm
d) ± 0.50 mm
Answer: b
Clarification: In Ultrasonic Machining the dimensional accuracy levels are limited to ± 0.05mm.
7. Conicity resulting after machining by Ultrasonic Machining can be reduced by?
a) Direct injection of slurry
b) Tools having negative taper
c) High static pressure
d) All of the mentioned
Answer: d
Clarification: Conicity can be reduced by above means and also by using wear resistant tools, finer abrasive particles etc.
8. Typical roundness error in graphite, resulted due to lateral vibrations is between?
a) 01 – 20 μm
b) 20 – 60 μm
c) 60 – 100 μm
d) 100 – 150 μm
Answer: b
Clarification: The roundness is between 20 – 60 μm while machining graphite by Ultrasonic Machining.
9. Typical roundness error in glass, resulted due to lateral vibrations is between?
a) 01 –20 μm
b) 20 – 40 μm
c) 40 – 140 μm
d) 150 – 250 μm
Answer: c
Clarification: The roundness is between 40 – 140 μm while machining graphite by Ultrasonic Machining.
10. Which of the following factors affect the surface finish of machined parts in Ultrasonic Machining?
a) Amplitude
b) Material
c) Tool surface
d) All of the mentioned
Answer: d
Clarification: The above factors influence the surface quality of the machined parts in Ultrasonic Machining very significantly.
11. What is value of surface finish achieved, when we use the abrasive of grit number 240?
a) 0.01 – 0.08 μm
b) 0.08 – 0.13 μm
c) 0.13 – 0.25 μm
d) 0.25 – 0.38 μm