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EndsemMay 20232019 patternBE Mech

Quality & Reliability Engineering (QRE) SPPU Endsem Question Paper May 2023

All 8 questions from this SPPU endsem paper, as printed. Read them here or open the PDF.

Open the PDFMost repeated QRE questions
Subject code
402050 A
Pattern
2019 pattern
Exam
Endsem
Session
May 2023
Max. marks
70
Time
2½ Hours
Semester
VIII
Paper code
[6004]-618

Printed for: B.E. (Mechanical)

Instructions to the candidates

  1. Answer Q.1 or Q.2, Q.3 or Q.4, Q.5 or Q.6, Q.7 or Q.8.
  2. Draw suitable neat diagrams, whenever necessary.
  3. Figures to the right indicate full marks.
  4. Assume suitable data if necessary.

Questions

  1. Q1

    1. a)

      Explain following basic concepts of Reliability (Any 4): i) Failure Rate (  (t)) ii) Hazard Rate (h(t)) iii) MTTF iv) MTBF v) Probability Density Function (PDF) vi) Cumulative Distribution Function (CDF)

      [8]
    2. b)

      What is Reliability? Distribution between Quality and Reliability of a product. Explain the causes of Unreliability in mechanical system.

      [9]

  2. Q2

    1. a)

      What are the different modes of Failure? Draw & explain a specimen ‘Bath Tub Curve’ showing various life characteristic phases/regions.

      [8]
    2. b)

      The failures of brakes of Ten Automobiles are observed to be 43500, 52000, 72000, 84500, 93500, 101000, 111500, 116000 & 123500 miles of operations. Plot the probability density, probability distribution, reliability and the hazard function of the failure time to brakes. 2

      Also asked:May 2025

      [9]

  3. Q3

    1. a)

      Calculate the reliability of the system shown in following Fig. (1). The value shows the reliability of individual components in the system.

      [10]
    2. b)

      This part has equations that don’t show as text. Open the PDF to read it.

      [8]

  4. Q4

    1. a)

      Evaluate the Reliability of System shown in following Fig. (2) By Conditional Probability Approach.

      [10]
    2. b)

      A system consists of three units connected in series, with reliabilities R 1 = 0.70,R 2 = 0.80 and R 3 = 0.9. It is desired that the reliability of the system to be 0.65. How should this be apportioned among three units by Minimum Effort Method? 3

      Also asked:Nov 2023

      [8]

  5. Q5

    1. a)

      What is FMECA? Give the procedure of FMECA. State importance of RPN in FMECA, with example.

      Also asked:Nov 2025 ·May 2025 ·Nov 2023

      [8]
    2. b)

      Fig. (3) shows three valves, A, B and C, a pump (P), a pipeline and a tank to collect water pumped from the pond. Construct the fault tree corresponding to the top event “No Flow of Water Into The Tank”.

      [9]

  6. Q6

    1. a)

      Write Short notes on(Any 2): i) Fault Tree Analysis. ii) Ishikawa for failure representation (Cause Effect Diagram) iii) Symbols used in FTA

      Also asked:Nov 2025 ·Nov 2023

      [8]
    2. b)

      For an emergency operation theatre in a hospital, the power is obtained from the main city supply through a transformer connected is series. To ensure an uninterrupted supply, an auxiliary generator is also used with a suitable switch over. Refer Fig. (4). The probability of failure of the main city supply is 0.01 and transformer reliability is 0.996. The auxiliary power generator has a reliability factor of 0.99. Draw a block diagram for the system. Construct the fault tree and calculate reliability of the system. 4

      [9]

  7. Q7

    1. a)

      Define Maintainability and Availability for the system from the following data collected at a plant. Mean time before failure: 35 Hrs. Mean time to repair: 10 Hrs. Administrative and logistic time: 50% of MTTR Calculate operational availability and inherent availability of the plant.

      Also asked:Nov 2025 ·Nov 2023

      [8]
    2. b)

      A beam is subjected to mean stress 180 N/mm 2 and standard deviation 20 N/mm 2 . The mean strength of beam material is 280 N/mm 2 and standard deviation 40 N/mm 2 . (Given: for Z = -2.24, Area = 0.4875) Determine: i) Reliability of the beam. ii) Minimum factor of safety. iii) Average factor of safety.

      Also asked:May 2025

      [10]

  8. Q8

    1. a)

      What is meant by Accelerated test in evaluating Reliability? Give at least six point differences between Highly Accelerated Life Testing (HALT) and Accelerated Life Testing(ALT)

      Also asked:Nov 2023

      [8]
    2. b)

      This part has equations that don’t show as text. Open the PDF to read it.

      [10]