1. What causes infant mortality in mechanical equipments?
a. Design errors
b. Manufacturing defects
c. Installation defects
d. All of the above
View Answer
ANSWER: d. All of the above
2.A plain carbon steel has mean yield strength of 300 N/mm2 and standard deviation of 50 N/mm2. What is the mean and standard deviation of margin of safety, if mean tensile stress of 250 N/mm2 and standard deviation of 65 N/mm2 acts on it?
a.
23.45 N/mm2, 50 N/mm2
b. 50 N/mm2, 82 N/mm2
c. 82 N/mm2, 7.07
N/mm2
d. 7.07 N/mm2, 50
N/mm2
View Answer
ANSWER: b. 50 N/mm2, 82 N/mm2
3. What is meant by mean time to failure (MTTF)?
a. Mean time between two successive
failure components
b. Maximum time between two
successive failure components
c. Sum of survival time for
number of components divided by number of failures
d. Sum of number of failures
divided by survival time for number of components
View Answer
ANSWER: c. Sum of survival time for number of components divided by number of failures
4. If a relief valve has reliability of 0.989, how many failures are expected in testing 1000 such relief valves?
a. 111
b. 100
c. 10
d. 11
View Answer
ANSWER: d. 11
5. Failure rate for safety valve working for 400 hours is 3 x 10–6 failures/hour. What is the reliability of safety valve?
a. 0.998
b. 0.989
c. 0.888
d. 0.899
View Answer
ANSWER: a. 0.998
6. What is meant by hazard rate?
a. Number of failures per unit time
per number of items when exposed for same time
b. Probability of test specimen
fails between time t1 and t1 + dt1 which
survives for time t1
c. Both a. and b.
d. None of the above
View Answer
ANSWER: c. Both a. and b.
7. What
is the standard deviation of clearance population for the diameter of shaft and
hole assembly specified below?
Shaft diameter = 30 ± 0.15
Hole diameter = 30.5 ± 0.25
a. 0.097 mm
b. 0.059 mm
c. 0.036 mm
d. 0.390 mm
View Answer
ANSWER: a. 0.097 mm
8. Which of the following curves have the mean value equal to zero in the graph of frequency vs random variable?
a. Normal distribution curve
b. Standard normal distribution
curve
c. Both a. and b.
d. None of the above
View Answer
ANSWER: b. Standard normal distribution curve
9. What is the relation between standard deviation(σ) and arithmetic mean (μ) to determine coefficient of variation (C)?
a. C = σ + μ
b. C = σ – μ
c. C = σ / μ
d. C = σ x μ
View Answer
ANSWER: c. C = σ / μ
10. Assignable causes are caused due to changes in _________
a. manufacturing process
b. material
c. inspection process
d. all of the above
View Answer
ANSWER: d. all of the above
11. A
designed experiment is a test or series of tests in which ____________ changes
are made to the input variables so that we may observe and identify
corresponding changes in the output response.
a) Systematic
b) Random
c) Purposeful
d) Non-purposeful
View Answer
Answer: c
Explanation: A designed experiment is a series of test in which we change the
input variables according to our choice to obtain a desired change in the
output. These changes are perfectly purposeful.
12. Which
of these does not come into the general model of a process?
a) Input
b) Controllable input factors
c) Uncontrollable inputs factors
d) Acceptance sampling
View Answer
Answer: d
Explanation: The general model of process describes a process to which the
input is provided in the presence of controllable factors and uncontrollable
input factors, to get an output.
13. The
uncontrollable factors are the factor ___________
a) That varies according to a normal distribution
b) That does not vary at all
c) That can be controlled by the user
d) That cannot be changed according to the wish of the user
View Answer
Answer: d
Explanation: There are two types of factors present with a process input while
running period of a process, the controllable, and the uncontrollable input
factors. The factors, which can be changed according to user’s wish, are called
the uncontrollable factors.
14. The
uncontrollable factors are also called ____________
a) Designed factors
b) Noise factors
c) Acceptance factors
d) Sound factors
View Answer
Answer: b
Explanation: The uncontrollable input factors are present when the process is
running, and these factors can’t be varied according to the user’s wish. So
these factors are also called the noise factors.
15. Which
of these steps are not conducted when the design of experiment procedure is
adopted?
a) Determining which variable is most influential to output
b) Determining where to set the influential controllable factors so that output
is near the nominal requirement
c) Deleting the uncontrollable factors
d) Determining where to set the influential controllable inputs so that the
variability in the output is smallest
View Answer
Answer: c
Explanation: While conducting the design of experiment procedure, we determine
the influential factors which affect the output, vary the determined variables
to get a required output value.
16.
Experimental design methods are not used ____________
a) Evaluating the process capability
b) In process development
c) In process troubleshooting to improve process performance
d) To obtain a process that is robust and insensitive to external sources of
variability
View Answer
Answer: a
Explanation: The experimental design methods may be used either in process
development or process troubleshooting to improve process performance, or to
obtain a process that is robust or insensitive to external variability causes.
17. The
designed experiments are the part of ___________ step of DMAIC process.
a) Define
b) Measure
c) Analyze
d) Control
View Answer
Answer: c
Explanation: The major procedure parts, which are used in the designing of the
experiments, are including the analysis of data and their improvement. So they
are an integral part of the Analyze and Improve step of DMAIC process.
18. The
design of the experiment is used to determine the variables which are
___________ affecting the state of the process.
a) The most
b) The least
c) Not
d) Not changing or
View Answer
Answer: a
Explanation: The design of the experiment procedure is, determining the variables
which most affect the process state and the output. We vary these variables to
get a relationship between them and the output.
19. Which
of these can be used to develop a new process?
a) Design of experiments
b) Acceptance sampling
c) Control charts
d) Histogram
View Answer
Answer: a
Explanation: The design of the experiment procedure is an active statistical
method, which can be used to control the values of the output, by obtaining the
relationship between the input factors and output. SO this can be used to
design a new process with great process capability.
20. Which
of these can be obtained by using the Experimental design?
a) Reduced process capability
b) Increased variability
c) Increased cost
d) Reduced distance from the nominal value
View Answer
Answer: d
Explanation: With the use of the designed experiments, it is possible to
increase the conformance of the product to the nominal value. So it can be used
in designing a new product.
21. Which
of these can be used in the DFSS activities?
a) Design of experiments
b) Histogram
c) Acceptance sampling
d) Stem and Leaf plot
View Answer
Answer: a
Explanation: The DFSS activities are said to be the Design for Six-sigma
activities. The process of design of experiments is very useful in these
activities.
22. The
DFSS stands for _______________
a) Deleting for smaller standards
b) Degradation for Six-sigma
c) Design for six-sigma
d) Development for six-sigma
View Answer
Answer: c
Explanation: The DFSS stands for the Design for Six – Sigma activities. These
activities are used to setup a process environment to get the six-sigma output.
23. SPC
and Design of experiments are very closely interrelated.
a) True
b) False
View Answer
Answer: a
Explanation: SPC and experimental design of experiments are two very interrelated
tools for process improvement and optimization. For example, if a low Cp
process is in-control; Designed experiments could be used to increase process
capability.
24. SPC
is a passive statistical method.
a) True
b) False
View Answer
Answer: a
Explanation: SPC is a passive statistical method as, in this procedure; we have
to wait for the process information to come, to decide a step to control the
process. However, if the process is in-control, we can’t do very much to reduce
the variability.
25. Which
of these can be used in the process of engineering design?
a) Design of experiment
b) Control charting
c) Acceptance sampling
d) Cusum charts
View Answer
Answer: a
Explanation: The design of experiments can also play a major role in
engineering design activities, where new products are developed and existing
ones are improved. So this is also used in DFSS activities.
26. Which
of these is not an application of experimental design in the field of the
Engineering design?
a) Evaluation and comparison of basic design configurations
b) Evaluation of material alternatives
c) Evaluation of key product design parameters that impact performance
d) Evaluation of correct process to develop the product
View Answer
Answer: d
Explanation: The Design of the experiment procedure helps in engineering design
by helping in evaluation of material alternatives, key product design
parameters, and basic design configurations.
27. Use
of designed experiments does not give _________
a) Improved yield
b) Reduced variability
c) Closer conformance to the nominal
d) Increased development time
View Answer
Answer: d
Explanation: The use of the design of the experiments procedure is quite useful
in process development. This gives an improved yield, reduced variability and
closer conformance to nominal, and reduced development time.
28. Which
of these is not a correct statement for Acceptance Sampling?
a) Concerned with inspection of products
b) Concerned with decision making regarding products
c) One of the oldest aspects of quality assurance
d) One of the oldest aspects of quality control
View Answer
29. Which
technique was used majorly in 1930s and 1940s for incoming or receiving
inspection?
a) SPC
b) Histogram
c) c-chart
d) Acceptance sampling
View Answer
Answer: d
Explanation: Acceptance sampling was one of the major components of the field
of statistical quality control, and was used primarily for incoming and
receiving inspection, in the 1930s and 1940s.
30.
Decision making regarding the lot disposition is sometimes called _____________
a) Lot rejection
b) Lot acceptation
c) Lot sentencing
d) Lot wording
View Answer
Answer: c
Explanation: Based on the acceptance sampling information, there is decision
making regarding the lot information. This decision is either to accept or
reject the lot. So it is called, the Lot Sentencing.
31.
Acceptance sampling can be used as _____________
a) Incoming inspection activity
b) Outgoing inspection activity
c) Both, incoming and outgoing inspection activity
d) Neither incoming nor outgoing inspection activity
View Answer
Answer: c
Explanation: The Acceptance sampling is customarily thought to be the receiving
or incoming inspection activity, but there are a few cases where it can be used
as the outgoing inspection activity.
32. The
purpose of Acceptance sampling is to _____________
a) Sentence lots
b) Estimate lot quality
c) Estimate lot defectives
d) Estimate lot conformity
View Answer
Answer: a
Explanation: The Acceptance sampling procedure is necessarily a lot sentencing
procedure. It cannot be used to estimate the lot quality or lot conformity to
the standard specifications.
33. Which
of these procedures doesn’t provide a direct form of quality control?
a) Control charts
b) Acceptance sampling
c) Design of experiments
d) Cusum charts
View Answer
Answer: b
Explanation: The Acceptance sampling procedure doesn’t provide a direct form of
quality control. Acceptance sampling simply accepts and rejects lots; even if
all lots are of same quality, some are accepted and some are not.
34. Which
of these can be used as an audit tool to ensure the output of a process
conforms to requirements?
a) Cusum charts
b) EWMA charts
c) Acceptance sampling
d) np-charts
View Answer
Answer: c
Explanation: The most effective use of acceptance sampling is not to “inspect
quality into the product”, but rather as an audit tool to ensure that the
output is similar to the required specifications.
35. Which
of these is not used in sampling?
a) 0% inspection
b) 100% inspection
c) Acceptance sampling
d) 5% inspection
View Answer
Answer: d
Explanation: There are generally three techniques used in the inspection of a
lot; first is 0% inspection, second is 100% inspection, and third is acceptance
sampling.
36. The
no-inspection alternative of sampling is used when ______________
a) The supplier’s process is so good that defective units are never encountered
b) The supplier’s process is so bad that almost every unit is defective
c) The component is extremely critical
d) The component is moderately critical
View Answer
Answer: a
Explanation: When the supplier’s process is so good that the defective units
are never encountered. This shows that the supplier process capability is quite
high.
37. When
is the 100% inspection done?
a) The supplier’s process is so good that defective units are never encountered
b) The supplier’s process is so bad that almost every unit is defective
c) The component is extremely critical
d) The component is moderately critical
View Answer
Answer: c
Explanation: The option of full inspection is chosen only when the product
component is extremely critical, and can affect the whole product performance
when used defective, e.g. aircraft nuts and bolts.
38.
Acceptance sampling is not used when _____________
a) The test is destructive
b) The cost of 100% inspection is quite high
c) The supplier’s process capability is very high
d) Although the supplier process is satisfactory but a program is needed for
continuous monitoring
View Answer
Answer: c
Explanation: The acceptance sampling is used when the test is destructive, or
the cost of 100% inspection is quite high, or when we need a continuous
monitoring program.
39. When
the inspection error rate is sufficiently high, which of these is used as the
sampling technique?
a) 0% inspection
b) 100% inspection
c) 50% inspection
d) Acceptance sampling
View Answer
Answer: d
Explanation: When there are many items to be inspected and the inspection error
rate is sufficiently high, that 100% inspection might cause a high % of
defective units to be passed, the procedure of acceptance sampling is adopted.
40. Which
of these is not used for a lot quality inspection purposes?
a) EWMA Control chart
b) Cusum chart
c) Shewhart control charts
d) Acceptance Sampling
View Answer
Answer: d
Explanation: The Acceptance sampling procedure is used for decision making of
either acceptance or rejection of a lot. It can’t be used as a lot quality
estimators.
41.
Designed experiments may benefit the lot quality improvement process more than
the Acceptance sampling.
a) True
b) False
View Answer
Answer: a
Explanation: As Acceptance sampling is just a lot sentencing process, it can’t
estimate the quality of products in the lot. But designed experiments ensure
good quality of the process output before even production.
42. A
good lot can be rejected through the use of acceptance sampling.
a) True
b) False
View Answer
Answer: a
Explanation: As acceptance sampling considers only a particular number of
sample units, and does not make use of the data of other units, there is a
slight possibility that it will reject the good lot.
43. Which
of these is not an advantage of acceptance sampling over the 100% sampling
plan?
a) Less expensive
b) Highly costly
c) Applicable to destructive testing
d) Lesser manpower is needed
View Answer
Answer: b
Explanation: As lesser number of units are checked while using the acceptance
sampling plan instead of the 100% sampling plan, it is less expensive,
applicable to destructive testing, and needs lesser manpower.
44. Which
of these is used when the test of the component is non-destructive, cheap and
fast?
a) 0% inspection
b) Acceptance sampling
c) 100% sampling
d) 50% sampling
View Answer
Answer: d
Explanation: As it will give better results in the case of 100% inspection when
the test procedure of a component is non-destructive, cheap, and fast, the full
lot sampling procedure is adopted.
45. Which
has the lowest number of manpower required?
a) Acceptance sampling
b) 0% inspection
c) 100% inspection
d) 50% inspection
View Answer
Answer: b
Explanation: As 0% inspection does not need any equipment or personnel to check
the product component supplied by the supplier, it has the lowest number of
manpower required.
46..
Which has lesser probability of handling damage in between 100% inspection, and
the acceptance sampling procedure?
a) 100% inspection
b) Acceptance sampling
c) Both have equal handling damage
d) Can’t be predicted
View Answer
Answer: b
Explanation: As there is a lesser number of units used as samples in the
acceptance sampling, there is less handling of the product, and hence reduced
damage is there in the case of acceptance sampling.
47. Which
of these quite successfully fulfills the following sentence?
“The rejection of entire lots as opposed to the simple return of defectives
often provides stronger motivation to the supplier for quality improvements.”
a) 0% sampling
b) 100% sampling
c) Random % of the lot sampling
d) Acceptance sampling
View Answer
Answer: d
Explanation: As in the case of acceptance sampling, there are only a few units
selected to be returned to the supplier, instead of returning the whole lot, it
motivates the supplier for quality improvements.
48. Which
is the most expensive for the same testing process and product component to be
tested?
a) Acceptance sampling
b) 100% sampling
c) 0% sampling
d) 50% sampling
View Answer
Answer: b
Explanation: As the 100% sampling procedure requires the checking of whole lot,
it requires more resources to be devoted towards the sampling process. This
makes it the most expensive procedure of all.
49. Which
generates lesser information about the products and the manufacturing process,
100% sampling or Acceptance sampling?
a) 100% sampling
b) Acceptance sampling
c) Both generate equal amount of information
d) Can’t be predicted
View Answer
Answer: b
Explanation: As we there are lesser number of units as samples in the case of
acceptance sampling rather than the 100% sampling procedure, it generates
lesser information about the process and the product.
50. Which
has the most probability of rejecting the good lot?
a) Acceptance sampling
b) 100% sampling
c) 0% sampling
d) Can’t be predicted
View Answer
Answer: a
Explanation: As the 100% inspection accepts the lot after the inspection of
whole lot, and there are rarely any defectives in the case of no-inspection,
acceptance sampling is having the highest probability of rejecting the good
lot.
51. Which
of these requires planning and documentation of the sampling procedure?
a) Acceptance sampling
b) 100% sampling
c) 0% sampling
d) 50% sampling
View Answer
Answer: a
Explanation: The 100% sampling checks the whole lot, so it does not require any
planning or documentation, whereas the acceptance sampling requires it.
52. Which
of these does not require sampling documentation at all?
a) 0% sampling
b) 100% inspection
c) Acceptance inspection
d) 50% inspection
View Answer
Answer: a
Explanation: As there is no sampling done in the case of 0% inspection or
sampling, there is no need to do the documentation for the same. So it doesn’t
require any sampling documentation at all.
53. The elongation of a bar is 0.5 mm, when a tensile stress of 200 N/mm2 acts on it. Determine original length of a bar if modulus of elasticity is 150 x 103.
a. 375.93 mm
b. 300 mm
c. 360 mm
d. None of the above
ANSWER: a. 375.93 mm
54. Deformation per unit length is called as ________
a. strain
b. stress
c. modulus of elasticity
d. none of the above
ANSWER: a. strain
55. The process of creating mechanisms and shapes of mechanical elements for a machine to get the desired output for a given input is called as ___
a. analysis
b. innovation
c. synthesis
d. designing
ANSWER: c. synthesis
56. Which of the following is not a reason to design and redesign a product?
a. Optimum design
b. Innovation
c. Appearance
d. None of the above
ANSWER: d. None of the above
57. In design process, which process is followed after selecting the material?
a. Selecting factor of safety
b. Synthesis
c. Analysis of forces
d. Determining mode of failure
ANSWER: d. Determining mode of failure
58. Which design consideration deals with appearance of the product?
a. Ergonomics
b. Aesthetics
c. System design
d. Creative design
ANSWER: b. Aesthetics
59. The
objective of considering ergonomics in machine design is to ____
1. decrease physical stresses
2. make user adapt to the machine
3. make machine fit for the user
4. improve appearance of the product
a. only 2
b. 3 and 4
c. 1 and 3
d. 1, 3 and 4
ANSWER: c. 1 and 3
60. In stress-strain diagram, up to proportional limit ______
a. stress is inversely proportional
to strain
b. force is directly
proportional to displacement
c. stress is directly
proportional to strain
d. strain is directly
proportional to stress
ANSWER: c. stress is directly proportional to strain
70. Which of the following materials do not have a well defined yield point?
a. Heat
treated steel
b. Concrete
c. Carbon fiber
d. All of the above
ANSWER: d. All of the above
80. Factor of safety is the ratio of _________
a. working
stress and ultimate strength
b. yield strength and endurance
strength
c. ultimate strength and yield
strength
d. yield strength and working
stress
ANSWER: d. yield strength and working stress
81. In design process, which step is followed after defining the problem?
a. Analysis
b. Synthesis
c. Optimization
d. Evaluation
ANSWER: b. Synthesis
82. For brittle materials having static load, factor of safety is given as the ratio of ______
a. endurance strength and design
stress
b. design stress and allowable
stress
c. working stress and allowable
stress
d. ultimate strength and design
stress
ANSWER: d. ultimate strength and design stress
83. The ratio of endurance strength and allowable stress is used to determine FOS for _____
a. fatigue loading
b. static loading of brittle
materials
c. static loading of ductile
materials
d. all of the above
ANSWER: a. fatigue loading
84. Which of the following factors are not considered while selecting values for factor of safety?
a. Cost
b. Failure consequences
c. Degree of uncertainty about
loading and material
d. None of the above
ANSWER: d. None of the above
85. What is the step ratio for R40 series?
a. 1.44
b. 1.05
c. 4.0
d. 0.4
ANSWER: b. 1.05
86. The application factor depends on ______
a. prime mover
b. hours of operation per day
c. machine driven
d. all of the above
ANSWER: d. all of the above
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