## Metrology and Quality Control - Dec 2016

### Mechanical Engg (Semester 5)

TOTAL MARKS: 100

TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.

(2) Attempt any **four** from the remaining questions.

(3) Assume data wherever required.

(4) Figures to the right indicate full marks.

### Solve any one question.Q1(a,b) Q2(a,b)

**1(a)** Differentiate between systematic errors and random errors.(5 marks)

### Solve any one question.Q1(a,b) Q2(a,b)

**1(a)** Draw a neat sketch of Vernier caliper and How to calculate least count of Vernier caliper give one example.(4 marks)
**1(b)** State different types of comparators, explain sigma comparator in detail.(5 marks)
**1(b)** write short notes on

i) Types of standards

ii) Electrical comparator (LVDT)(6 marks)
**2(a)** Describe with neat sketches of auto-collimator and sine bar.(5 marks)
**2(a)** Write short notes on universal measuring machine(5 marks)
**2(b)** State different types of linear and angular measuring instruments, explain any two with example.(5 marks)
**2(b)** Explain angle Dekker with neat sketch.(5 marks)

### Solve any one question.Q3(a,b) Q4(a,b)

**3(a)** State and explain Taylor's Principle of Gauge Design with example.(5 marks)

### Solve any one question.Q3(a,b) Q4(a,b)

**3(a)** Explain Interferometry applied to flatness testing by using optical flat(5 marks)
**3(b)** Optical arrangement of interferometer for testing flatness of surfaces.(5 marks)
**3(b)** Determine the dimensions and tolerances of shaft and hole having size of 30H7f8 fit. (IT7=16i,

IT8=25i, D is in a step 18-30mm, Fundamental deviation for f=-5.5D^{0.41}(5 marks)
**4(a)** What is surface texture? State different methods to analyze surface trace.(5 marks)
**4(a)** Derive an expression for best wire size for measuring effective diameter Calculate Effective diameter and best wire diameter for M22×2.5 screw plug gauge by using Floating carriage Micrometer for which reading were taken as Diameter of standard cylinder 20 mm Micrometer reading over standard cylinder with two wire is=15.9334mm Micrometer reading over plug screw gauge with two wire is=15.2245mm(6 marks)
**4(b)** A machine operator needs a guage for checking the diameter of bores being machined to diameter 20+0.06 mm. What should be the dimensions (diameter) of the guage if unilateral system of tolerances are incorported? Assume gauge tolerance and wear allowance each 10% of work tolerance.(5 marks)
**4(b)** Write short notes on Gear tooth vernier caliper.(4 marks)

### Solve any one question.Q5(a,b) Q6(a,b)

**5(a)** Explain PDCA & PDSA Cycle.(8 marks)

### Solve any one question.Q5(a,b) Q6(a,b)

**5(a)** Explain Deming's cycle and 14 point towards quality improvement.(8 marks)
**5(b)** Describe different quality costs.(8 marks)
**5(b)** Explain seven old quality tools.(8 marks)
**6(a)** Write short note on: Juran's Trilogy(8 marks)
**6(a)** Explain the concept of quality circle and their structure and limitation.(8 marks)
**6(b)** Differentiate between Quality Assurance & Quality control.(8 marks)
**6(b)** What is cost of quality? Explain its types.(8 marks)

### Solve any one question.Q7(a,b,c) Q8(a,b,c)

**7(a)** Ten samples of parts were taken from a production line For 100% inspection, each sample containing 300 parts. The total number of defection was 350. Compute upper and lower conrol limit.(5 marks)

### Solve any one question.Q7(a,b) Q8(a,b)

**7(a)** Control chart for X overline is to be prepared for a certain dimension of component the sub group size is 4 after 20 sub group it is found that $$\sum \bar{X}=825.60mm$$ and ∑R=5.60 mm compute the central line and the control limits for X overline chart d2 for sub group size 4=2.059. If the specified dimension is41.0±+0.40mm and the above process is in the control and is normally distributed, can it meet the specification requirement? If not, determine the percentage of rejection.(8 marks)
**7(b)** Explain analysis on out control condition refering control charts.(5 marks)
**7(b)** Explain the following OC curve characteristics

i) Changing of lot size

ii) Changing of sample size

iii) Changing of acceptance number

iv) Changing of sample size and acceptance number.(8 marks)
**7(c)** Explain in detail with flow chart single sampling and double sampling plan.(8 marks)
**8(a)** A new process is started, and the sum of sample standard devitation for 25 subgroups of size 4 is 750. If the specifications are 700 ±80, what is process capability index? What action would you recommand take for four samples factor for centeline=c4=0.9213(6 marks)
**8(a)** Exlain the Multiple sampling plan with flow chart(8 marks)
**8(b)** Ten casting were inspected in order to locate defect in them after in spection total 37 defects were found. Compute control limit for c-Chart.(4 marks)
**8(b)** Define producer risk; consumer risk and AOQL and AOQ for the given data calculate sample size and AOQ for single sampling plan.

i) Probability of acceptance for 0.4% defective in a lot is 0.558.

ii) Lot size N= 10000

iii) np'=1.6 & c=1

iv) Defectives found in the sample are not to be replaced.(8 marks)
**8(c)** Write note on PPAP and OC curve.(8 marks)
**9** Write short note on(any four)

a) Cauuse & effect diagram

b) Pareto diagram

c) Kaizen

d) TPM

e) 5 s

f) J I T(16 marks)
**9** Explain the following terms(Any Three)

a) KANBAN

b) JIT

c) FMECA

d) DMAIC

e) FIVE S(18 marks)