Basic Electrical Electronics Engineering,  Basic Mechanical Engineering,  Instrumentation & Measurement

Measurement Viva Questions Part-2

Measurement Viva Questions

Measurement Viva Questions, Viva Questions on Measurement, Instrumentation Viva Questions, Engineering Viva Questions, Short Type Viva Questions

Measurement Viva Questions Part-1

Short Type Viva Question and Answers

Q.1. Classify the lathe machine.

Ans. On the basis of their purpose, design, the number of tools, accommodate, degree of mechanism, and other factors lathe machine tools may be classified as:

  • Low production machine
  • Medium production machine
  • High production machine

Q.2. What is a drilling machine?

Ans. A Drilling machine is one of the simplest moderate and accurate machine tools used in the production shops and tool-room.

Q.3. Who do you understand by the operation of drilling?

Ans. Drilling is an operation through which holes are produced in a solid metal by means of a revolving tool called a drill. It is considered a roughing Operation.

Q.4. What are the tools that are used for drilling?

Ans. The tool used for drilling is called a drill. The commonly used drill can be classified in many ways as follows:

  1. According to the type of shank they carry

(a) Parallel shank

(b) Taper shank

  • According to the type of flutes

(a) Flat drills

(b) Twist drills

  • According to length

(a) Short series drills

(b) Stub series drill

  • According to applications 

(a) Core drills

(b) Drills for long drilling

(c) Centre drill

(d) Masonry drills

  • According to the tool material

(a) High-speed steel drill

(b) Carbide tipped drills

Q.5. Write the various operations performed on the drilling machine.

Ans. There is a number of operations done on the drilling machine which are as follows:

  • Drilling
  • Reaming
  • Boring
  • Counter boring
  • Counter sinking
  • Spot Facing
  • Tapping

Q.6. How will you designate a drilling machine?

Ans. Drilling machines are designated by the dimensions in mm which will roughly give the diameter of the largest hole that can be drilled at its center under the machine.

Q.7. What is Reaming?

Ans. When very close dimensional accuracy is to be maintained, drilling forms only the basic operation. For such holes, drilling is followed by another operation called reaming.

Q.8. What is cutting speed?

Ans. The cutting speed is a measure of the peripheral speed of the drill in meters per minute. Mathematically, it is expressed as:

Cutting speed = πDN

where D = drill diameter, N = rpm.

Q.9. When using the strain-gauge system for stress/force/displacement measurements how are inbuilt magnification and temperature compensation achieved?

Ans. Four strain gauges are used connected in Wheatstone bridge configuration to achieve built-in magnification and temperature compensation.

Q.10. Which method of milling would you recommend for peripheral milling with carbide tooth cutters and why?

Ans. Down-cut milling is recommended because the radial force on the cutter is very high initially in the case of up-cut milling which causes rapid wear of cutter edges and has the effect of work hardening the surface. In down cut milling the radial force increases gradually and is constant most of the time and thus cutter life with brittle teeth improves considerably.

Q.11. What are strain gauge rosettes and what are their applications?

Ans. The arrangement of train gauges in the shape of a rase is referred to as a strain gauge rosette. His usually used for the measurement of strain in both transverse and longitudinal directions.

Q.12. What is meant by accuracy?

Ans. The accuracy of a measurement system is the closeness of the instrument output to the true value of the measured quantity.

Q.13. What are the uses of pyrometers? What are the types of pyrometer?

Ans. Pyrometers are used to measure high temperature (more than 650°) two types in common use are:

  • Total radiation pyrometer
  • Optical pyrometer (Disappearing filament type).

Q.14. What is meant by optical torsion meter?

Ans. Torque is measured by means of measuring relative angular displacement of two graduated transparent sector discs mounted on the shaft at a convenient distance. When the torque is applied to the shaft disc more relative to each other corresponding to the angular twist of the shaft and this displacement is reading through the eyepiece of an optical system, whose light source illuminates the transparent sector of the discs.

Q.15. Define transducer.

Ans. The transducer is an element that converts the signal from one physical form to another. Without changing the information content of the signal.

Q.16. Give some properties of errors.

Ans.

  • Errors give the difference between the measured value and the true value.
  • Accuracy of a measurement system is measured in term of error.
  • A study of error helps in finding the reliability of the results.

Q.17. What is static pressure? How is it measured?

Ans. The pressure caused on the walls of a pipe due to a fluid at rest inside the pipe or due to the flow of a fluid parallel to the walls of the pipe is called static pressure. This static pressure is measured by inserting a pressure-measuring tube into the pipe carrying the fluid so that the tube is at a right angle to the fluid flow path.

Q.18. What is a thermopile?

Ans. It is the arrangement of several thermocouples in series with all measuring junctions at one temperature and all reference junctions at another in order to achieve high sensitivity.

Q.19. What are energy storing elements in mechanical, electrical, thermal, hydraulic, and pneumatic systems?

Ans.

  • Mechanical: Mass and Springs
  • Electrical: Inductor and Capacitor
  • Thermal: Thermal Capacitance
  • Hydraulic: Hydraulic inertia and Capacitance
  • Pneumatic: Pneumatic inertia and Capacitance

Q.20. Define Feed.

Ans. The feed of drill is the distance, which it moves parallel to its axis into the work on every revolution of the drill and is generally expressed in mm/min.

Q.21. What is the depth of the cut?

Ans. In a drilling operation, the depth of cut is measured at a right angle to the axis of the drill i.e., the direction of feed.

Depth of cut = \frac{drill dia}{2}

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