Advanced Machining Questions and Answers – LBM-Applications – 2

This set of Advanced Machining Processes Problems focuses on “LBM-Applications – 2”.

1. Peak power should be increased in Laser drilling process by __________ pulse energy.
a) Increasing
b) Decreasing
c) Reducing
d) Constant
View Answer

Answer: a
Explanation: Required peak power in the laser drilling process can be obtained by increasing the pulse energy while keeping the pulse duration constant.

2. Drilling of holes with larger pulse duration causes which effect to the holes produced?
a) Enlarge holes
b) Reduce hole size
c) Decrease the depth
d) All of the mentioned
View Answer

Answer: a
Explanation: Drilling the holes with larger pulse duration causes enlargement of the hole entrance.

3. What are pulse duration values used for laser drilling?
a) 0.01 to 0.25 ms
b) 0.1 to 2.5 ms
c) 1 to 25 ms
d) 10 to 250 ms
View Answer

Answer: b
Explanation: Value of the duration of the pulse range from 0.1 to 2.5 ms.
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4. _________ pulse energy and _________ pulse duration are suitable for drilling.
a) Low, short
b) Low, long
c) High, short
d) High, long
View Answer

Answer: c
Explanation: In LBM, high energy pulses and low pulse duration are more suitable for hole drilling in aerospace materials.

5. Which of the following are the functions of assist gases?
a) Removal of molten material
b) Shield the lenses
c) Better efficiency
d) All of the mentioned
View Answer

Answer: d
Explanation: 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.

6. Selection of assist gas depends on which of the following properties of work piece?
a) Material
b) Thickness
c) Material & Thickness
d) None of the mentioned
View Answer

Answer: c
Explanation: The selection of different assist gases depends on the work piece material and its thickness.

7. Which of the following properties of material affect the quality of holes obtained?
a) Reflectivity
b) Absorption coefficient
c) Thermal conductivity
d) All of the mentioned
View Answer

Answer: d
Explanation: Quality of holes depend on reflectivity, absorption coefficient, thermal conductivity, density, specific heat, and latent heat of material.
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8. What range of powers are used for cutting through steel?
a) 1 to 20 W
b) 20 to 100 W
c) 200 to 1000 W
d) 1 to 20 kW
View Answer

Answer: c
Explanation: The power ranges from 200 W to 1 kW for cutting through steel.

9. Which gas jet assisted process is suitable for most of the metals?
a) Oxygen gas
b) Nitrogen gas
c) Helium gas
d) All of the mentioned
View Answer

Answer: a
Explanation: Oxygen-jet assistance is used for most metals, as the gas liberates additional energy by the exothermal chemical reactions.
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10. What happens to the cutting speed with an increase in the work piece?
a) Increases
b) Decreases
c) Enhances
d) Remains same
View Answer

Answer: b
Explanation: The cutting speed of the process of drilling decreases with an increase in the thickness of the work piece material.

11. What is the full form of LBT in the processes of LBM?
a) Laser Beam Tempering
b) Laser Beam Templating
c) Laser Beam Texturing
d) Laser Beam Tinning
View Answer

Answer: c
Explanation: Full form of LBT is Laser beam texturing which is an application of Laser beam machining.

12. Depth and the crater size depends on which of them below?
a) Energy of beam
b) Dwell time of beam
c) Energy & Dwell time of beam
d) None of the mentioned
View Answer

Answer: c
Explanation: Depth and the crater size depend on the energy and the dwell time of beam.

13. Where are the textured surfaces used that are obtained in LBT?
a) Mould makings
b) Bearings
c) Printer roll manufacturing
d) All of the mentioned
View Answer

Answer: d
Explanation: Textured surfaces obtained in LBT are widely used in mold making, bearings and printer roll manufacturing.

14. The roll is _________ and the laser beam is moved ________ along the roll.
a) Stationary, axially
b) Stationary, perpendicularly
c) Rotated, axially
d) Rotated, perpendicularly
View Answer

Answer: c
Explanation: In texturing process of LBT, the roll is rotated and laser is moved axially along the roll.

15. State whether the following statement is true regarding the texturing in LBT.
“In LBT, hardness of the material is a limitation to the process.”
a) True
b) False
View Answer

Answer: b
Explanation: In Laser beam texturing, hardness of material is not a limitation to the process.

Sanfoundry Global Education & Learning Series – Advanced Machining.

To practice problems on all areas of Advanced Machining, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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