Unconventional Machine Process Set 14

Mechanical Engineering

Practice Mode Previous Next
On This Page

This set of Unconventional Machine Process (UMP) Multiple Choice Questions & Answers (MCQs) focuses on Unconventional Machine Process Set 14

Q1 | What happens when the heat is diffused into bulk material?
  • phase change occurs
  • melting occurs
  • vaporization may take place
  • all of the mentioned
Answer: all of the mentioned
Explaination:
the heat diffusion into bulk material causes phase change, melting or vaporization in the materials.
Q2 | What happens to the process efficiency if plasma plumes are formed in LBM?
  • increases
  • enhances
  • decreases
  • improves
Answer: decreases
Explaination:
in laser beam machining, the process efficiency is reduced due the absorption and scattering loses when plasma plumes are formed.
Q3 | Machining of LBM takes place when power density is                          than what is lost by conduction and radiation.
  • greater
  • smaller
  • lower
  • same as
Answer: greater
Explaination:
machining of laser takes place when power density is greater than what is lost by conduction, convection and radiation.
Q4 | Which of the following phenomenon take place before melting and evaporating in LBM?
  • conduction
  • reflection
  • absorption
  • all of the mentioned
Answer: all of the mentioned
Explaination:
material in lbm is removed through several effects such as conduction, absorption, reflection following melting and evaporation.
Q5 | What happens to the material removal rate when reflectivity is higher?
  • will decrease
  • will increase
  • will enhance
  • remains same
Answer: will decrease
Explaination:
in lbm, as the reflectivity of the metals is increased the material removal rates of the process are decreased.
Q6 | Reflectivity of the materials depends on which of the following factors?
  • wave length
  • properties of material
  • surface finish
  • all of the mentioned
Answer: all of the mentioned
Explaination:
reflectivity of the materials depends on wavelength, the properties of materials, surface finish and temperature.
Q7 | How much amount of incident radiation is reflected at lower power densities?
  • 10 percent
  • 20 percent
  • 50 percent
  • 90 percent
Answer: 90 percent
Explaination:
most of the metals reflect nearly 90 percent of incident radiation if the power densities are low.
Q8 | How are minimum energies required for plastics when compared to that required for metals?
  • lower than
  • higher than
  • same as
  • none of the mentioned
Answer: lower than
Explaination:
the minimum energies required for plastic are lower than that required for metals.
Q9 | Which of the following has high machining speeds in Laser Beam Machining?
  • metals
  • non metals
  • metal alloys
  • all of the mentioned
Answer: non metals
Explaination:
non metallic material machine at higher speeds than metallic ones due to higher reflectivity in metallic materials
Q10 | Which of the following are the applications of Laser Beam Machining?
  • drilling
  • cutting
  • texturing
  • all of the mentioned
Answer: all of the mentioned
Explaination:
drilling, cutting and grooving, texturing and structuring, milling and dressing etc.., are the applications of laser beam machining process.
Q11 | State whether the following statement is true or false regarding the drilling using LBM. “Compared to LBM, conventional machining is more accurate and efficient.”
  • true
  • false
Answer: false
Explaination:
conventional machining is less sufficient than laser beam machining because of their material toughness.
Q12 | Other non-conventional processes lay behind Laser beam machining in drilling process because of which factors below?
  • high cost
  • long lead times
  • low machining speeds
  • all of the mentioned
Answer: all of the mentioned
Explaination:
other non-conventional processes need high costs for tools, long lead times, and low machining speeds when compared to lbm.
Q13 | Laser drilling has proven to be more efficient in which of the following factors?
  • cost
  • quality
  • reliability
  • all of the mentioned
Answer: all of the mentioned
Explaination:
laser drilling has proven to be an efficient one in terms of cost, quality, and reliability for large-scale production applications.
Q14 | Which of the following are different laser drilling processes in Laser beam machining?
  • direct drilling
  • drill and ream
  • trepanning
  • all of the mentioned
Answer: all of the mentioned
Explaination:
laser drilling can be performed by three methods that are – direct (percussion) drilling, trepanning, drill and ream.
Q15 | The hole size in direct drilling depend up on which of the factors below?
  • input power
  • focusing adjustments
  • input power & focusing adjustments
  • none of the mentioned
Answer: input power & focusing adjustments
Explaination:
the hole size in the direct drilling method of laser drilling process, depend on input power and focusing adjustments.
Q16 | Which method mentioned below is used for drilling of large size holes?
  • direct drilling
  • drill and ream
  • trepanning
  • all of the mentioned
Answer: trepanning
Explaination:
trepanning method of laser drilling process is used for drilling large holes either by rotating or moving the part.
Q17 | What is the value the maximum optimum depth that can be machined using Laser drilling process?
  • 0.17 mm
  • 1.7 mm
  • 17.1 mm d) 171.7 mm
Answer: 1.7 mm
Explaination:
the maximum depth obtained when by using laser drilling is about 1.7 mm.
Q18 | What is the depth-to-diameter ratio obtained in drilling process using Laser beam machining?
  • 10:1
  • 20:1
  • 50:1
  • 80:1
Answer: 50:1
Explaination:
value of the maximum depth-to-diameter ratio obtained in drilling using laser beam machining is 50:1.
Q19 | What is the maximum value of drilling depth in trepanning method of laser drilling process?
  • 1.7 mm
  • 4.3 mm
  • 6.4 mm
  • 7.9 mm
Answer: 6.4 mm
Explaination:
the depth increases when we use a trepanning method for laser drilling process and that is about 6.40 mm.
Q20 | What is the value of minimum corner radius obtained by drilling in Laser beam machining?
  • 0.10 mm
  • 0.25 mm
  • 0.50 mm
  • 0.65 mm
Answer: 0.25 mm
Explaination:
the value of the minimum corner radius obtained while drilling using lbm is about 0.25 mm
Q21 | Peak power should be increased in Laser drilling process by                      pulse energy.
  • increasing
  • decreasing
  • reducing
  • constant
Answer: increasing
Explaination:
required peak power in the laser drilling process can be obtained by increasing the pulse energy while keeping the pulse duration constant.
Q22 | Drilling of holes with larger pulse duration causes which effect to the holes produced?
  • enlarge holes
  • reduce hole size
  • decrease the depth
  • all of the mentioned
Answer: enlarge holes
Explaination:
drilling the holes with larger pulse duration causes enlargement of the hole entrance.
Q23 |                    pulse energy and                    pulse duration are suitable for drilling.
  • low, short
  • low, long
  • high, short
  • high, long
Answer: high, short
Explaination:
in lbm, high energy pulses and low pulse duration are more suitable for hole drilling in aerospace materials.
Q24 | Which of the following are the functions of assist gases?
  • removal of molten material
  • shield the lenses
  • better efficiency
  • all of the mentioned
Answer: all of the mentioned
Explaination:
assist are used to remove the molten material, it also shield the lenses from expelled material and they are also used for obtaining better process efficiencies.
Q25 | Selection of assist gas depends on which of the following properties of work piece?
  • material
  • thickness
  • material & thickness
  • none of the mentioned
Answer: material & thickness
Explaination:
the selection of different assist gases depends on the work piece material and its thickness.
Previous Next