Metrology & Quality Engineering - Dec 2015

Mechanical Engineering (Semester 6)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Differentiate between precision and accuracy.(5 marks) 1 (b) What do you mean by quality of design?(5 marks) 1 (c) What do you mean by waviness and roughness?(5 marks) 1 (d) Explain advantages and limitations of pneumatic comparators.(5 marks) 2 (a) Explain Taylors Principle of Gauge design with suitable example.(5 marks) 2 (b) Explain principle, construction and working of Parkinson's Gear Tester.(10 marks) 3 (a) Explain principle of interference. How flatness can be checked with the help of optical interferometer.(10 marks) 3 (b) How will compromise between quality and cost. Explain different types of cost of quality with suitable examples.(10 marks) 4 (a) Explain following terms with respect to surface roughness parameters -
i) R_a
ii) R_z
iii) RMS(10 marks) 4 (b) Control Chart for X and R are kept on the weight in kilograms of a colour pigment for a batch process. After 25 subgroups with subgroup size of 4.
$ \sum \overline{x}=52.08 \ kg \\\\ \sum R=11.82 $
Assuming process is in state of control, Compute the X and R chart central line and control limits.
(For subgroup size of 4, A2=0.729 D4=2.282 D3=0 d₂=2.059).(10 marks) 5 (a) Explain two wire method used in screw thread measurement.(10 marks) 5 (b) Explain various modern SQC tools.(10 marks) 6 (a) Explain single and double samplings plans. Also explain concept of OC curves.(10 marks) 6 (b) Explain construction and working and applications of 3D coordinate measuring machine.(10 marks)