I’m working on a mechanical engineering exercise and need an explanation and answer to help me learn.
complete the End of Chapter Questions.
1. Accuracy can only be checked by comparisonwith:a. another technician or metrologistb. a trade groupc. a higher standardd. your boss
2. Measurement is most important to which one ofthe following applications?a. Mass production of automotive partsb. Mass production of aircraft partsc. One-of-a-kind handicraftsd. All manufacturinge. Manufacturing Qf parts from prepared plans
3. Measurement involves fundamental quali ties. Select three qualities from the followinglist.a. Roundnessb. Massc. Flatnessd. Timee. Weightf. Modules of elasticityg. Lengthh. Widthi. Hardness.
4. Which of the following best defines “dimen sional metrology?”a. The measurements required to manufactureproductsb. Measurements found by the use of scales andother measuring instrumentsc. The measurement of lines, areas, volumes,and anglesd. The measurement of real things, whether theybe steel, wood, plastic, or any other materiale. The measurement of lines, circles, and angles
5. Select one or more of the following that are notconsidered to be dimensional metrology.a. Bolt circle spacingb. The selection of lubricants for a given bearingallowancec. The torque requirement for a bolted assemblyd. The tolerance required for a shaft in a bearinge. The size limits of a mass-produced replace ment part
6. The role of the inspector in industry emergedas the result of which one of the followingcircumstances?a. Weapons were first mass produced.b. Gunpowder changed the threat from weapons.c. Foremen could not keep up with mass pro duction rates.d. The piece-part system was introduced.e. Precision measurement tools such as the mi crometer were introduced to industry.
7. Of the following characteristics, select the onesthat affect quality control.a. Employee moraleb. Pride of productc. Dimensional measurementsd. Environmental conditionse. Product specifications
8. For every act of dimensional metrology, oneor more of the following variables may apply.Identify the single most important variable.a. Number of decimal placesb. Metric or customary systemc. Reliabilityd. Repeatabilitye. Sensitivity
9. In this text, metrological methods or principlesare emphasized rather than the measuring in struments themselves. There are several reasonsfor this. Which of the following is the most im portant reason?a. There is no complete agreement about theinstruments.b. Instrument manufacturers provide detailedinformation.c. Principles are more interesting than methodsof use.d. Principles and methods are easily adaptableto all instruments.
10. Small errors can cost a company billions of dol lars or have dire consequences. Discuss the po tential impact that small errors can have in thefollowing industries: Automotive Aerospace Biotech/Medical
1. Ambiguity is the enemy of dimensional metrol ogy. Which of the following best describes afigure with four sides, each of which is 21/2in. inlength?a. Polyhedronb. Parallelepipedc. Squared. Parallelogram
2. The principal dimensional measurement islength. Which of the following is the best defini tion of length?a. A dimensionb. The shortest distance between two pointsc. The number of units of measurement thatseparates two pointsd. The opposite of width
3. Which of the following terms is not essential indefining a length measurement?a. Reference pointb. Unit of measurementc. Toleranced. Measured point
4. In which one or more of the following charac teristics does a dimension differ from a length?a. A dimension is an intended size, whereas alength is the measured size.b. A length may be a decimal, but a dimension isa whole number.c. A dimension must be determined by mea surement, whereas a length is stated on thedrawing of the part.d. Lengths have tolerances, whereas dimensionsdo not.
5. The primary purpose of dimensional measure ment is to:a. show how precise a part isb. show how close the manufacturer can pro duce partsc. justify the priced. communicate the designer’s intent
6. Which of the following is an international stan dards body?a. ISOb. ABCDc. GD & Td. A2Z
7. When measurements are repeatedly taken onthe same unit, the extent to which an instru ment replicates its measurements is:a. accuracyb. rangec. precisiond. discrimination
8. Which of the following best describes the refer ence point?a. Point at which any measurement beginsb. Position identified on a drawing as the end ofa measurementc. Furthest point from the measured pointd. Highest point above the reference plane 9. Which of the following is an American Dimen sioning and Tolerancing Standard?a. ASME Y14.5 2009b. MSNBCc. ISO 2001d. American Society of Training and Develop ment (ASTD)
10. Part features designate the portion of a part thatmay be considered separately from the partitself.a. Trueb. False
11. How many .001 inches are there in one inch?a. 1b. 100c. 1,000d. 10,000
12. Which of the following best defines an edge?a. The sharp corners of the partb. The intersection of a plane with anotherplanec. The cutting portion of an instrumentd. Conical section
13. Which of the following best describes malefeatures?a. Total lengths, heights, and widthsb. Round rods or tubular partsc. Features bounded by outside dimensionsd. Features larger than female features
14. If 1 mm equals 0.0394 inches, 700 millimetersequals how many inches?a. 35.53b. 275.8c. 27.58d. 0.003
15. The ability of two or more inspectors to obtainconsistent results repeatedly when measuringthe same set of parts and the same measuringinstruments is called:a. accuracyb. precisionc. reproducibilityd. error
16. One shooter fires 10 shots in a group 5 in. in di ameter but all are off the target. Then, a secondshooter has a group 10 in. in diameter but threeshots are through the X-ring. Which of the follow ing statements are the most likely to be correct?a. The first shooter is precise but not as accurateas the second shooter.b. The second shooter is the luckiest.c. The second shooter is both precise andaccurate.d. The first shooter is precise but inaccurate,whereas the second shooter is more preciseand more accurate.
17. Accuracy may be defined several ways. Whichof the following is correct?a. Accuracy is the measure of precision.b. Accuracy is the measure of conformity.c. Accuracy is the measure of reliability.d. Accuracy is the best synonym for precision.
18. Which of the following does reliabilitydepend on?a. High-grade measuring instrumentsb. Both accuracy and precisionc. Lots of luckd. Limited production
19. Can either accuracy or precision be improvedwithout respect for the other value? Select thecorrect statement.a. Neither can be changed without affecting theother.b. Either can be increased without affecting theother.c. Precision can be increased without an in crease in accuracy.d. Accuracy can have only a limited increasewithout requiring an increase in precision.
20. Tolerances are specified for machined parts forwhich of the following reasons?a. Manufacturing equipment has inherentvariation.b. To ensure proper fit between mating parts.c. The designer wasn’t sure of the exact mea surement to specify.d. Botha and b.
21. The earliest recorded length standard was:a. The ulnab. The length of the monarch’s footc. The cubitd. The Egyptian pyramids
22. What was the primary purpose of the earliestrecorded standard?a. To ensure the fair payment of taxesb. To practice early medicinec. To ensure that parts mated in buildingconstructiond. To mix cement in building the pyramids
23. What is the chief similarity between the use ofthis first recorded standard and present-daypractices?a. The high cost of reliable measurementb. The use of metal standardsc. The need for inches and fractions of inchesd. The requirement that working standardsagree with the master standard
24. The English system and the metric system dif fer in the origin of their standards. Which of thefollowing best describes those origins?a. The metric standards derived from the stan dards in use by the crafts guilds, whereas theEnglish standards were those used by thepeasants and small merchants.b. Both were by decree of the existinggovernments.c. The metric standards were derived from thediameter of the earth, whereas the English stan dards were selected by the House of Parliament.d. The metric standards were placed in force bythe Revolutionary Committee, whereas theEnglish standards were already in use.
25. Why have light waves replaced metal bars asthe master standards of length?a. Platinum-iridium bars are very expensive,but light is free.b. They are easier to use in the dark.c. Light wave standards can be more easily repro duced, and to greater accuracy, than metal bars.d. The use of light waves avoids politicalconsiderations.
26. There are many ways that measurement sys tems can be compared. Which of the followingare the three best ways?a. Metrological superiority, computational ad vantage, and communications abilityb. Finest discrimination, greatest accuracy, andeasiest convertibilityc. Agreement among nations, historical prec edent, and general acceptabilityd. Lowest cost added to the manufacture ofproducts, most easily available gages and mea suring instruments, and easy-to-understandquality control procedures
27. Round off 25.7853901 to two significant decimals.a. 25.786b. 25.78c. 25.79d. 26
28. Each of the following lists is fully correct. How ever, one of them comes closest for defining thefour most essential qualities of a measurementsystem. Which is it?a. Greatest measuring ability; least errors; leasttime to conduct measurements; least destruc tion to workpieces while being measuredb. Lowest cost; widest range of direct measure ment; adaptability to angles, surface finishes,and radii as well as lengths; minimum errorsc. Easiest computations; self-canceling errors;clearly visible minimum scale divisions; samemeaning in all languagesd. Optimum measuring ability; minimum er rors; minimum time required to measure;minimum cost
29. Le Systeme International d’Unites is abbreviated as:a. LSIUb. SIc. IUd. mm
30. Which of the following are good reasons to usethe decimal-inch system?a. Convertibility in and out of the metric systemis easy.b. Rounding off is easier than it is with the Eng lish system using fractions.c. The finest division is close to the minimumresolving power of the human eye.d. It does not need to be calibrated to the inter national meter.
31. Which of the following correctly represents acentimeter and a kilometer?a. 1022, 103b. 101, 1021c. 103,102d. 1022, 104
32. Which of the following best explains the rea sons for rounding off?a. Elimination of numbers over 5b. Averaging the computational errorc. Elimination of meaningless digitsd. Simplifying computations
33. What is the exception to the rule for roundingoff?a. Values over 9 should be left undisturbed.b. Calculations involving values of differentdecimal places should not be rounded off.c. The final rounding should be obtained fromthe most precise value.d. Values beyond four decimal places shouldnot be rounded off.
34. Visit the ANSI web site at www.ANSLorg.What is the mission of ANSI? ,Identify the current ISO quality standard.