JNTU
JNTU B.Tech III ENGINEERING METROLOGY Previous Question Paper (November/December - 2018 - R13)
Part A is compulsory. Part B consists of 5 Units. Answer any one full question from each unit.
Part A
What is the advantage of interchangeable assembly?
Answer
The primary advantage of interchangeable assembly is that any component from a batch can be assembled with any corresponding mating part without manual adjustment or selective fitting. This significantly reduces assembly time, lowers production costs, and facilitates mass production and easy field replacement of parts.
Why it is necessary to give tolerance on engineering dimension?
Answer
Tolerances are necessary because it is physically impossible to manufacture a part to an exact theoretical dimension due to machine inaccuracies, tool wear, and operator skill. Tolerances ensure functional interchangeability, maintain consistent product quality, and allow for economic manufacturing by defining the permissible range of variation.
What are the sources of error in sine bar?
Answer
Sign in to view the complete answer paper.
What are the factors that determine the accuracy or sensitivity of a spirit level?
Answer
Sign in to view the complete answer paper.
Differentiate between flat and smooth surface.
Answer
Sign in to view the complete answer paper.
What is a straight edge?
Answer
Sign in to view the complete answer paper.
Draw the ISI symbols for surface finish.
Answer
Sign in to view the complete answer paper.
The heights of peak and valleys of 18 successive points on a surface are 30, 25, 46, 37, 19, 41, 21, 40, 18, 42, 24, 40, 25, 40, 40, 18, 37, 21 microns respectively, measured over a length of 20mm. Determine CLA and RMS values of roughness surface.
Answer
Sign in to view the complete answer paper.
List out various screw thread parameters for metrological measurement.
Answer
Sign in to view the complete answer paper.
List out various characteristics of a comparator.
Answer
Sign in to view the complete answer paper.
Part B
Explain clearly what is meant by the system of limits and fits. Why this system is used in engineering practice?
Answer
Sign in to view the complete answer paper.
Explain the terms ‘Clearance’, ‘Interference’ and ‘Allowance’ with respect to the mating conditions of a shaft and a hole.
Answer
Sign in to view the complete answer paper.
Describe the principal features of Indian standard system of limits and fits for screwed work.
Answer
Sign in to view the complete answer paper.
A hole and shaft system had the following dimensions: 60 H 8 / c 8. The multiplier of grade 8 is 25. The fundamental deviation for ‘C’ shaft is – (9.5 + 0.8 D). The diameter step is 50 – 80. Design the suitable ‘GO’ and ‘NO-GO’ gauges for shaft and hole.
Answer
Sign in to view the complete answer paper.
Explain the working principle of spirit level.
Answer
Sign in to view the complete answer paper.
With the help of neat sketch explain the construction and working of a dial indicator.
Answer
Sign in to view the complete answer paper.
Explain the working principle of tool maker’s microscope. What are the uses and specific applications of tool maker’s microscope? Explain.
Answer
Sign in to view the complete answer paper.
How will you check the periodic errors in micrometers with the help of optical flats?
Answer
Sign in to view the complete answer paper.
Explain the uses of optical flats.
Answer
Sign in to view the complete answer paper.
Sketch and explain the working of Taylor-Hobson talysurf surface roughness measuring instrument.
Answer
Sign in to view the complete answer paper.
In the measurement of surface roughness, heights of 10 successive peaks and valleys were measured from a datum as follows: Peaks: 45 42 40 35 35 μm; Valleys: 30 25 25 24 18 μm. Determine the RZ value of the surface.
Answer
Sign in to view the complete answer paper.
Describe various methods of numerical assessment of surface finish.
Answer
Sign in to view the complete answer paper.
Calculate the Ra value of a surface for which the sampling length was 8.0mm, the graph was drawn to a vertical magnification of 1000 and the areas above and below the datum line were given (Above: 180, 90, 155, 55mm2; Below: 70, 90, 170, 150mm2).
Answer
Sign in to view the complete answer paper.
Describe various alignment tests to be conducted on drilling machines.
Answer
Sign in to view the complete answer paper.
Suggest and explain an effective method of determining the variation in drunken thread.
Answer
Sign in to view the complete answer paper.
Explain the working principle of pneumatic comparator.
Answer
Sign in to view the complete answer paper.
Suggest and explain the method of measurement of gear tooth thickness.
Answer
Sign in to view the complete answer paper.