Question 1

Ultrasonic machining (USM): identify the incorrect statement Evaluate the properties of USM for hard/brittle materials (e.g., glass, ceramics). Choose the statement that is wrong for ultrasonic machining.

Accepted Answer

Given / Concept USM uses high-frequency vibrations with an abrasive slurry to micro-chisel brittle materials. It is non-thermal and well-suited to glass, carbides, and ceramics. Why option (c) is wrong USM has low MRR compared to conventional cutting or grinding; it does not remove large amounts of material rapidly. Validation of other options (a) True — ideal for brittle, hard materials.(b) True — MRR is slow.(d) True — produces fine features and good finishes without heat-affected zones. Final Answer It removes large amount of material quickly.

Question 2

Chip formation vs tool edge condition  When the cutting edge becomes dull due to wear, what chip type is most likely to appear (under typical ductile-work cutting)? Choose the best answer.

Accepted Answer

Concept A dull tool increases friction and temperature at the tool–chip interface, promoting built-up edge on ductile materials. BUE causes poor surface finish and fluctuating cutting forces. Eliminations (a) Clean continuous chips are more typical with sharp tools and good lubrication.(b) Discontinuous chips are more typical with brittle materials or very low cutting speeds, not solely due to dullness.(d) Chip formation continues unless cutting stops. Final Answer Continuous chips with a built-up edge (BUE) on the tool.

Question 3

Lathe design: progression of available spindle speeds  Many engine/toolroom lathes use a stepped speed box. Identify how the series of spindle speeds is typically arranged.

Accepted Answer

Concept Stepped speeds are chosen in geometric progression so that surface speed changes in a fixed percentage step, which better matches cutting-speed recommendations across diameters and materials. Final Answer Geometrical progression (constant ratio).

Question 4

Thread cutting tool geometry: ideal rake selection  For a single-point thread cutting tool, which rake setting is ideal to preserve thread form accuracy and edge strength? Choose the best option.

Accepted Answer

Approach A zero top rake keeps the included profile angle of the thread unchanged and provides a strong cutting edge for intermittent loads typical during threading. Notes Some materials may allow small positive rake with corrective geometry, but the standard teaching is zero rake to preserve the exact thread form. Final Answer Zero rake angle (flat top).

Question 5

Twist drill nomenclature: identify the helix angle vs point angle  Evaluate the statement about a twist drill: “The angle included between the two lips, projected on a plane parallel to the drill axis and parallel to the two cutting lips, is called …

Accepted Answer

Definitions Point angle: included angle between the two cutting lips (commonly ~118° for general-purpose drills).Helix angle: angle between the direction of the helical flute and the drill axis (commonly ~25°–35°). Conclusion The statement given defines the point angle, not the helix angle. Final Answer Incorrect — that is the point angle; helix angle is between flute helix and axis.

Question 6

Grinding methods: producing a straight or tapered surface on a workpiece  Select the grinding operation typically used to generate flat straight or flat tapered surfaces on a part. Choose the correct method.

Accepted Answer

Concept Surface grinding uses a horizontal/vertical spindle with a reciprocating or rotary table to produce accurate flat surfaces; by tilting/setting, it can also produce a controlled taper on flat faces. Why others do not fit Internal/external cylindrical grinding generate cylindrical or conical (round) surfaces, not flat planes.Form grinding is intended for reproducing a specific profile/contour via the wheel form. Final Answer Surface grinding.

Question 7

Single-point tool geometry: purpose of side rake angle  Side rake influences chip flow direction and shear deformation. Evaluate the statement: “Side rake angle on tools is provided to control chip flow.”

Accepted Answer

Concept Side rake changes the effective shear plane and influences chip direction and thickness, improving chip evacuation, reducing cutting force, and enhancing surface finish. Notes Clearance angles prevent rubbing; rake angles influence cutting mechanics and chip formation. Final Answer True — side rake primarily controls chip flow and reduces cutting forces.

Question 8

Twist drill helix angle vs. driving torque at a given feed  For a standard twist drill (typical helix ≈ 30°), how does changing the helix angle affect the torque needed to drive the drill at the same feed? Choose the correct condition that increases…

Accepted Answer

Concept/Approach The drill's helix angle affects the effective rake angle at the cutting lips and the ease of chip evacuation. A smaller helix reduces effective rake, increasing cutting resistance and the torque required. Step-by-step reasoning • Decrease in helix → decrease in effective rake → higher shear deformation and friction.• Chip evacuation worsens, adding to torque demand. Verification Conversely, a larger helix increases effective rake and eases chip flow, generally reducing torque for the same feed/material. Final Answer Helix angle less than 30°

Question 9

Lathe tooling direction: best travel for a left-hand tool  Identify the most efficient traverse direction for cutting with a left-hand single-point tool on a lathe. Choose the correct travel direction along the bed.

Accepted Answer

Concept Left-hand tools are ground to cut efficiently when moving from left to right. Right-hand tools cut efficiently from right to left. Why others are incorrect The compound slide option is about feed direction control, not the fundamental efficient cutting direction for a left-hand tool; facing is a different operation. Final Answer From left to right end of the lathe bed

Question 10

Effect of end cutting edge angle on tool life  Consider the end cutting edge angle in single-point turning tools and its influence on edge rubbing and heat. State how a larger end cutting edge angle affects tool life.

Accepted Answer

Concept/Approach A larger end cutting edge angle reduces rubbing of the end flank against the newly machined surface, lowering frictional heating and wear. Step-by-step reasoning • Larger angle → better end clearance → less contact/rubbing.• Less heat at the end flank → slower wear progression → longer life. Final Answer Increases tool life

Question 11

The angle on which the strength of the tool depends is

Accepted Answer

rake angle

Question 12

In centreless grinding, the surface speed of regulating wheel is

Accepted Answer

15 to 60 m/min

Question 13

Which of the following statement is correct regarding grinding of high carbon steel?

Accepted Answer

all of the above

Question 14

In metal cutting, use of low feeds and high cutting speeds is desired when the objective is

Accepted Answer

surface finish

Question 15

While cutting helical gears on a non-differential gear hobber, the feed change gear ratio is

Accepted Answer

inter-related to index change gear ratio

Question 16

The relation between tool life (T) and cutting speed (V) is VTn = Constant. In this relation, the value of n depends upon

Accepted Answer

tool material

Question 17

When the end of a tap is tapered for about three or four threads, it is known as a

Accepted Answer

second tap

Question 18

The example of snag grinding is

Accepted Answer

all of these

Question 19

Which of the following statement is correct for orthogonal cutting system?

Accepted Answer

all of the above

Question 20

The type of tool used on lathe, shaper and planer is

Accepted Answer

single point cutting tool

Production Engineering Questions