Machining MCQ Quiz โ Questions 1โ25
1
Which machining process is typically used for high-precision finishing and achieving very tight tolerances?
Correct: Grinding Grinding uses abrasive wheels to remove small amounts of material and is used to get high surface finish and tight dimensional tolerances.
2
The Taylor tool life equation is usually expressed as VยทT^n = C. What does V represent?
Correct: Cutting speed In the Taylor equation V is cutting speed (usually in m/min or ft/min), T is tool life and n,C are empirical constants.
3
Which parameter most directly controls the material removal rate (MRR) in turning?
Correct: Feed ร depth ร speed MRR (volume/time) in turning is proportional to feed rate ร depth of cut ร cutting speed (converted to consistent units).
4
Which of the following is a non-conventional/non-traditional machining process?
Correct: EDM EDM removes material by controlled electrical discharges between an electrode and the workpieceโnon-mechanical removal.
5
What is ‘built-up edge’ (BUE) during metal cutting?
Correct: Material adhesion on tool BUE forms when work material welds to the cutting edge, altering geometry and surface finish; it can break off intermittently causing poor finish.
6
Which tool material is commonly used for high speed machining of steel at high cutting speeds?
Correct: Cemented carbide Carbide tools withstand higher temperatures and retain hardness at high cutting speedsโcommonly used for high-speed machining.
7
Which chip type indicates continuous chips and generally good surface finish in ductile materials?
Correct: Continuous chip Continuous chips form with ductile materials under conditions of good tool sharpness and appropriate cutting parametersโusually gives good finish.
8
What is the primary mechanism of material removal in Laser Beam Machining (LBM)?
Correct: Fusion and vaporization LBM removes material mainly by melting and vaporizing it with a high-intensity focused laser beam.
9
Which non-traditional process uses a stream of abrasive particles accelerated by water to erode material?
Correct: AWJM Abrasive water jet machining uses high-pressure water with abrasive particles to cut/erode materialsโsuitable for materials sensitive to heat.
10
What is ‘crater wear’ on a cutting tool?
Correct: Wear on rake face Crater wear is the depression on the rake face produced by high temperature and chemical action during cutting.
11
In EDM, which of the following is the dielectric fluid commonly used?
Correct: Hydrocarbon oils EDM commonly uses hydrocarbon dielectric fluids (like kerosene or special EDM oils) to cool and flush away debris and provide proper sparking conditions.
12
What does ‘nose radius’ of a single-point cutting tool affect?
Correct: Surface finish & tip strength A larger nose radius improves surface finish but increases cutting forces; too large can cause chatter or poor finish in sharp corners.
13
Which operation removes a small amount of material by rubbing and abrasive particles to achieve a mirror-like finish?
Correct: Lapping Lapping is a fine abrasive process to achieve very smooth surfaces and tight dimensional accuracy.
14
Which parameter largely controls chatter in milling operations?
Correct: Spindle speed & depth of cut Chatter is a dynamic instability influenced by spindle speed, depth of cut, tool overhang and machine-tool-workpiece stiffnessโstability lobe diagrams help choose speeds.
15
Which finishing process is best for improving geometric accuracy and surface finish of internal cylindrical bores?
Correct: Honing Honing is used to improve dimensional accuracy, roundness, and surface finish of internal bores beyond what reaming achieves.
16
Which machining operation uses a toothed tool to remove material in a single linear stroke?
Correct: Broaching Broaching uses a multi-tooth tool pulled or pushed in one stroke to cut complex internal/external profiles with very good accuracy.
17
In ultrasonic machining (USM), the material removal mechanism is primarily:
Correct: Abrasive erosion USM uses high-frequency vibration of an abrasive slurry causing micro-chippingโsuitable for brittle materials and delicate shapes.
18
Which process removes material by anodic dissolution under controlled conditions?
Correct: ECM ECM removes metal by anodic dissolution in an electrolyte under controlled currentโno tool wear and good for difficult-to-cut alloys.
19
Which factor primarily reduces tool life during machining?
Correct: Excessive speed/temperature High cutting speeds and temperatures accelerate tool wear mechanisms (diffusion, oxidation, crater wear) thus reducing tool life.
20
Which surface finish parameter indicates the average deviation of a surface profile from the mean line?
Correct: Ra Ra is the arithmetic mean of the absolute deviations from the mean line and is the most commonly used surface roughness parameter.
21
Which coolant/lubricant mechanism helps reduce friction and temperature at the cutting zone?
Correct: Boundary lubrication & convective cooling Cutting fluids act by forming boundary films to reduce friction and by convective cooling to remove heat from the cutting zone.
22
Which machining operation is most suitable to cut internal splines & keyways in one pass?
Correct: Broaching Broaching can cut internal splines, keyways or complex profiles in a single stroke with high accuracyโideal for high-volume production.
23
What is the effect of increasing feed rate on surface roughness during turning (other things constant)?
Correct: Surface worsens Increasing feed increases the height of feed marks leading to higher Ra (poorer finish), though MRR increases.
24
Which measurement technique is commonly used for internal bore surface finish measurement?
Correct: Profilometer Small stylus profilometers or bore gauges with stylus attachments are used to measure internal surface roughness (Ra, Rz).
25
Which of these is a correct strategy to reduce tool wear during high-speed machining?
Correct: Use coolant & advanced tools Using suitable cutting fluids and modern coated carbides or ceramics reduces friction, lowers temperature, and extends tool life at high speeds.
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