MT II MCQ QB - A mcq practice materials as a study guide PDF

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ME8451-MANUFACTURING TECHNOLOGY-II UNIT -4 ABRASIVE PROESSES AND BROACHING 1. What is broaching? a) A machining process used for increasing the size of the existing hole b) A machining process used for grinding hardened steel c) A machining process used for making intricate holes accurately d) A machining process for removal of a layer of material of desired width and depth Answer: d Explanation: Broaching is a machining process for removal of a layer of material of desired width and depth usually in one stroke by a slander rod or bar type cutter called as, having a series of cutting edges with a gradually increased protrusion. 2. What is the main advantage of broaching over shaping process? a) Use of single point cutting tool which are inexpensive and can be grounded to any shape b) Thin or fragile jobs can be conveniently machined because of lower cutting forces c) Surfaces with obstruction can also be machined d) Removal of the whole material in one stroke Answer: d Explanation: In shaping, attaining full depth requires a number of strokes to remove the material in thin layers step-by-step by gradually in feeding the single point tool. Whereas, broaching enables remove the whole material in just a single stroke by gradually rising teeth of the cutter called broach. Some are the advantages of shaping process and surfaces with obstruction cannot be machined by broaching.

3. Why push type broaches are made shorter in length? a) To reduce machining time b) To increase the efficiency c) For easy handling of the tool d) To avoid buckling Answer: d Explanation: Both pull and push type broaches are made in the form of slander rod or bar of varying section having along its length one or more rows of cutting teeth with increasing height. Also very high forces are generated during the machining. Therefore, push type broaches are made shorter in length to avoid buckling as they are subjected to compressive load. 4. How many types of broaches are there? a) 3 b) 5 c) 8

d) 9 Answer: d Explanation: Various types of broaches have been developed and are used for a wide range of applications. Types of broaches are as follows, (1) Pull type (2) Push type (3) Ordinary cut type (4) Progressive cut type (5) Solid type (6) Sectional type (7) Modular type (8) Profile sharpened type (9) Form relieved type.

5. Which of the following broaches are re-sharpened by grinding at rake faces? a) Form relieved type b) Modular type c) Profile sharpened type d) Sectional type Answer: a Explanation: Form relieved type broaches are sharpened and re-sharpened by grinding at their rake faces. These broaches have more complex cutting edge geometry and varies point-topoint along the cutting edges. Here the product is the replica of the tool form.

6. Which of the following grinding machine will give a better result for rough machining? a) Fine grain b) Very fine grain c) Coarse grain d) None of the mentioned Answer: c Explanation: Coarse grain wheel will give better metal removal rate and space for chip removal as rate of chip flow in rough machining is high.

7.Which of the following grinding wheel specified in ISO designation will represent Vitrified bond? a) Z 46 K 5 E 17 b) C 600 K 5 B 17 c) C 8 K 5 R 17 d) A 80 K 5 V 17 Answer: d Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “V” represents Vitrified bond type.

8. Material removal rate in grinding operation is small due to a) Negative rake angle

b) Positive rake angle c) Zero rake angle d) Material removal rate does not depend on the rake angle Answer: a Explanation: Grinding wheel have negative rake angle and hence have very small material removal rate. Hence grinding is mostly use as a finishing process.

9. Which of the following statements are true for centreless grinding? 1. Less metal needs to be removed in centreless grinding operation 2. The setup time for centreless grinding operation is small 3. The requirement of wheel adjustment in centreless grinding operation is minimum 4. The centreless grinding operation can be applied equally to both internal and external grinding a. (1), (2) and (3) b. (2), (3) and (4) c. (1), (3) and (4) d. (1), (2) and (4) ANSWER: (1), (3) and (4)

10. The grinding process results in good surface finishing because a. the chip removed during the process is small b. the process is carried out at high cutting speed c. both a. and b. d. none of the above ANSWER: both a. and b. 11. Grain number of grinding wheel is ___ to grain size. a) Directly proportional b) Inversely proportional c) Does not depend d) None of the mentioned View Answer Answer: b Explanation: Grain number = 1/(grain size). Grain number is similar to density of grains on grinding wheels. 12. Which of the following is a correct range for grain number of the grinding wheel for coarse grains? a) 220-600

b) 80-180 c) 30-60 d) 10-24 View Answer Answer: d Explanation: For coarse grain, grain number ranges from 10 to 24. 13. Which of the following is the correct range for grain number of the grinding wheel for medium grains? a) 220-600 b) 80-180 c) 30-60 d) 10-24 View Answer Answer: c Explanation: For medium grain, grain number ranges from 30 to 60. 14. Which of the following is a correct range for grain number of the grinding wheel for fine grains? a) 220-600 b) 80-180 c) 30-60 d) 10-24 View Answer Answer: b Explanation: For fine grains, grain number ranges from 80 to 180. 15. Which of the following is the correct range for grain number of the grinding wheel for very fine grains? a) 220-600 b) 80-180 c) 30-60 d) 10-24 View Answer Answer: a Explanation: For very fine grains, grain number ranges from 220 to 600. 16. Which of the following grinding machine will give a better result for rough machining? a) Fine grain b) Very fine grain c) Coarse grain d) None of the mentioned View Answer Answer: c Explanation: Coarse grain wheel will give better metal removal rate and space for chip removal as

rate of chip flow in rough machining is high. 17. Which of the following grinding machine will give a better result for finish machining operation? a) Fine grain b) Medium grain c) Coarse grain d) None of the mentioned View Answer Answer: c Explanation: Fine grain wheel will give smaller metal removal rate and hence better for finishing operations. 18. Which of the following symbol’s range of alphabet represent soft grain in grinding wheel? a) A – H b) I – P c) Q – T d) T – Z View Answer Answer: a Explanation: A-H represents soft grains in grinding wheel. 19. Which of the following symbol’s range of alphabet represent medium hardness grain in grinding wheel? a) A – H b) I – P c) Q – T d) T – Z View Answer Answer: b Explanation: I-P represents medium hard grains in grinding wheel. 20. Which of the following symbol’s range of alphabet represent hard grain in grinding wheel? a) D – H b) I – P c) A – D d) Q – Z View Answer Answer: a Explanation: A-H represents soft grains in grinding wheel. 21. Grinding wheel specified as “C 8 K 5 R 17” in ISO designation. What is the type of bond present in grinding wheel?

a) Vitrified b) Rubber c) Shellac d) Epoxy View Answer Answer: b Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “R” represents rubber. 22. Which of the following grinding wheel specified in ISO designation will represent Resin bond? a) Z 46 K 5 E 17 b) C 600 K 5 B 17 c) C 8 K 5 R 17 d) A 80 K 5 V 17 View Answer Answer: b Explanation: Fifth place of ISO designation of the grinding wheel represents the type of bond and “B” represents resin bond. 23. Which of the following grinding wheel specified in ISO designation will represent Shellac bond? a) Z 46 K 5 E 17 b) C 600 K 5 B 17 c) C 8 K 5 R 17 d) A 80 K 5 V 17 View Answer Answer: a Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “E” represents shellac. 24. Grinding wheel specified as “A 8 K 5 P 17” in ISO designation. What is the type of bond present in grinding wheel? a) Vitrified b) Rubber c) Shellac d) Epoxy View Answer Answer: d Explanation: Fifth place of ISO designation of the grinding wheel represents a type of bond and “P” represents rubber. 25. Which of the following will not have open structure? a) A 46 K 5 B 17 b) C 600 K 8 B 17

c) C 8 K 5 9 17 d) A 80 K 10 B 17 View Answer Answer: a Explanation: Fourth place of ISO designation of the grinding wheel represents Structure and “5” comes under dense structure. UNIT -5

CNC MACHININING

1. Which machine tool reduces the number of set-ups in machining operation, time spent in setting machine tools and transportation between sections of machines? a. Computer Numerical Control machine tool b. Direct Numerical Control machine tool c. Adaptive Control Systems d. Machining centre ANSWER: d. Machining centre 2. Part-programming mistakes can be avoided in a. NC (Numerical Control) machine tool b. CNC (Computer Numerical Control) machine tool c. Both a. and b. d. None of the above ANSWER: CNC (Computer Numerical Control) machine tool 3.Several machine tools can be controlled by a central computer in a. NC (Numerical Control) machine tool b. CNC (Computer Numerical Control) machine tool c. DNC (Direct Numerical Control) machine tool d. CCNC (Central-Computer Numerical Control) machine tool ANSWER: c. DNC (Direct Numerical Control) machine tool 4. Which of the following options is correct for the control unit and panel of NC (Numerical Control) and CNC (Computer Numerical Control) machine tools? a. The control unit of NC machine tool works in ON-line mode and the control unit of CNC machine tool works in batch processing mode b. The control unit of NC machine tool works in batch processing mode and the control unit of CNC machine tool works in ON-line mode c. The control units of both NC and CNC machines work in ON-line mode d. The control units of both NC and CNC machines work in batch processing mode

ANSWER: b. The control unit of NC machine tool works in batch processing mode and the control unit of CNC machine tool works in ON-line mode 5. In NC (Numerical Control) machine tool, the position feedback package is connected between a. control unit and programmer b. programmer and machine tool c. control unit and machine tool d. programmer and process planning ANSWER: c. control unit and machine tool 6. Which of the following statements are correct for CNC machine tool? 1. CNC control unit does not allow compensation for any changes in the dimensions of cutting tool 2. CNC machine tool are suitable for long run applications 3. It is possible to obtain information on machine utilization which is useful to management in CNC machine tool 4. CNC machine tool has greater flexibility 5. CNC machine can diagnose program and can detect the machine defects even before the part is produced a. (1), (2) and (3) b. (2), (4) and (5) c. (3), (4) and (5) d. (2), (3), (4) and (5) ANSWER: c. (3), (4) and (5) 7. The device, fed to the control unit of NC machine tool which sends the position command signals to sideway transmission elements of the machine, is called as a. controller b. tape c. feedback unit d. none of the above ANSWER: b. tape 8. Point-to-point systems are used for _____ facing parting reaming grooving Answer: reaming

9. Which of the following is not the advantage of CNC machines? Reduced scrap rate Improved strength of the components Higher flexibility Improved quality Answer: Improved strength of the components

10. Which of the following code is used in programming in incremental coordinates? a) G90 b) G91 c) G92 d) G94 View Answer Answer: b Explanation: G91 is used in programming in incremental coordinates. 11. CNC machining centres do not include operations like ______ a) milling b) boring c) welding d) tapping View Answer Answer: c Explanation: CNC machining centres are developed for machining prismatic components combining operations like milling, drilling, boring and tapping. Gradually machines for manufacturing cylindrical components, called turning centres are also developed. 12. The tool of an NC machine has to move along a circular arc from (5, 5) to (10, 10) while performing an operation. The centre of the arc is at (10, 5). Which one of the following NC tool path command performs the above mentioned operation ? (A) N010 GO2 X10 Y10 X5 Y5 R5 (B) N010 GO3 X10 Y10 X5 Y5 R5 (C) N010 GO1 X5 Y5 X10 Y10 R5 (D) N010 GO2 X5 Y5 X10 Y10 R5 ANSWER : Option (A) is correct. 13. NC contouring is an example of (A) continuous path positioning (B) point-to-point positioning (C) absolute positioning (D) incremental positioning

Option (A) is correct. NC contouring is a continuous path positioning system. Its function is to synchronize the axes of motion to generate a predetermined path, generally a line or a circular arc. 14. Which type of motor is NOT used in axis or spindle drives of CNC machine tools ? (A) induction motor (B) dc servo motor (C) stepper motor (D) linear servo motor Option (C) is correct. A spindle motor is a small, high precision, high reliability electric motor that is used to rotate the shaft or spindle used in machine tools for performing a wide rang of tasks like drilling, grinding, milling etc. A stepper motor have not all these characteristic due to change of direction of rotation with time interval. 15. What are the upper and lower limits of the shaft represented by 60 f8 ? Use the following data : Diameter 60 lies in the diameter step of 50-80 mm. Fundamental tolerance unit, i in μm = 0.45D1/3+ 0.001D Where D is the representative size in mm; Tolerance value for IT8 = 25i , Fundamental deviation for ‘ f ’ shaft =− 5.5D0.41 (A) Lower limit = 59.924 mm, Upper limit = 59.970 mm (B) Lower limit = 59.954 mm, Upper limit = 60.000 mm (C) Lower limit = 59.970 mm, Upper limit = 60.016 mm (D) Lower limit = 60.000 mm, Upper limit = 60.046 mm Answer : ( A) is correct.

Option (A) is correct. Since diameter 60 lies in the diameter step of 50 − 80 mm, therefore the geometric mean diameter. D = 50#80 = 63.246 mm Fundamental tolerance unit.

i = 0.45D1/3+ 0.001D 0.45(63.246)1/3 0.001 63.246 = + # = 1.856 μm = 0.00186 mm Standard tolerance for the hole of grades 8 (IT8) = 25i = 25#0.00186 = 0.0465mm Fundamental deviation for ‘ f ’ shaft ef =− 5.5D0.41 =− 5.5(63.246)0.41 =− 30.115 μm =− 0.030115mm Upper limit of shaft = Basic size + Fundamental deviation = 60 − 0.030115 = 59.970 mm Lower limit of shaft = Upper limit − Tolerance = 59.970 − 0.0465 = 59.924 16. Which of the following code will give point to point movement? a) G00 b) G01 c) G56 d) G94 View Answer Answer: a Explanation: G00 will give point to point movement. 17. Which of the following code will give linear interpolation movement? a) G00 b) G01 c) G78 d) G65 View Answer Answer: b Explanation: G01 will give linear interpolation movement. 18. Which of the following code will give circular interpolation in a clockwise direction? a) G56 b) G01 c) G02 d) G47 View Answer Answer: c Explanation: G02 will give circular interpolation in a clockwise direction. 19. Which of the following code will give circular interpolation in Counter clockwise direction? a) G00 b) G56

c) G69 d) G03 View Answer Answer: d Explanation: G03 will give circular interpolation in Counterclockwise direction. 20. Which the following code will produce dwell for a specified time? a) G18 b) G65 c) G45 d) G04 View Answer Answer: d Explanation: G04 will produce dwell for a specified time. 21. Which of the following code is used to give input of cutter offset data? a) G30 b) G20 c) G10 d) G04 View Answer Answer: c Explanation: G10 is used to give input of cutter offset data. 22. Which of the following code is used to select x y plane in milling? a) G18 b) G17 c) G10 d) G04 View Answer Answer: b Explanation: G17 is used to select x y plane in milling. 23. Which of the following code is used to select x z plane in milling? a) G18 b) G17 c) G10 d) G04 View Answer Answer: a Explanation: G18 is used to select x z plane in milling.

24. Which of the following code is used to select y-z plane in milling? a) G32 b) G00 c) G02 d) G19 View Answer Answer: d Explanation: G19 is used to select y-z plane in milling. 25. Which of the following code will change specified input values in millimeters? a) G01 b) G00 c) G20 d) G20 View Answer Answer: c Explanation: G20 will change specified input values in millimeters....