Instrumentation And Control Systems May2006 Rr220305

Set No. 1

Code No: RR220305

II B.Tech II Semester Regular Examinations, Apr/May 2006 INSTRUMENTATION AND CONTROL SYSTEMS ( Common to Mechanical Engineering, Production Engineering and Automobile Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. Explain the various physical principles involved in the operation of various categories of inductive transducers. [16] 2. What are mechanical Tachometers? Explain with examples. Describe the disadvantages of mechanical Tachometers. [16] 3. (a) Explain the principle behind the temperature measurement by radiation methods. (b) Explain the working of a total radiation in pyrometer.

[16]

4. (a) Explain, how an elastic diaphragm gauge is used to measure pressure with the help of relevant sketch. (b) List the limitations of elastic diaphragm gauge. (c) Discuss the merits and demerits of elastic sensing elements.

[8+4+4]

5. Explain the principle of operations of (a) Hot wire anemometer. (b) Turbine meter for the measurement of Fluid velocity.

[16]

6. (a) How relative humidity is measured using hygrometer? (b) A seismic type accelerometer is relatively rugged compared to a seismic type vibrometer. Comment. [16] 7. (a) Name the different sensors used to measure strain. Explain the working of any one type with neat sketch. (b) Draw any four types of strain gauge arrangement for measuring strain. [8+8] 8. Explain the following with suitable examples and block diagrams: (a) Temperature control. (b) speed control.

[16] ⋆⋆⋆⋆⋆

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Set No. 2

Code No: RR220305

II B.Tech II Semester Regular Examinations, Apr/May 2006 INSTRUMENTATION AND CONTROL SYSTEMS ( Common to Mechanical Engineering, Production Engineering and Automobile Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Describe about the step response of second order system. (b) A response test on a thermometer was thrust into temperature controlled bath of water maintained at 1000 C and the time was observed as the indicated temperature reached preselected values giving the following readings. Times(sec) Temp(deg c)

0.0 20

1.2 3.0 5.6 8.0 40 60 80 90

11.0 15.0 18.0 95 98 99

Draw the response curve on a graph paper and show that it follows closely the form of a simple lag with a time constant of 4 secs. [8+8] 2. (a) Explain the difference in principle of operation of a photo-emissive cell, a photo-conductive cell and a photo voltaic cell. Give the applications of each of these cells. (b) Differentiate between null mode and deflection of operation of measurement systems with examples. [16] 3. (a) With neat sketch explain the compensation method employed in pressure thermometer. (b) What is reference junction compensation? Why it is required for thermocouples? (c) Mention some advantage of thermocouples over other temperature sensors.[16] 4. (a) Discuss the working of a Bourdon tube pressure gauge with relevant sketch and mention their merits and demerits. (b) Explain the basic principle of working of a bellow type pressure gauges. (c) Sketch the various shapes of bellow used for pressure measurement. [4+8+4] 5. (a) List out the advantages and limitations of direct method of level measurement. (b) Describe with neat sketch the functioning of any two types of displacer type liquid level measuring instruments. [16] 6. (a) Explain the general theory of seismic instruments used for vibration/accelerator measurement. 1 of 2

Set No. 2

Code No: RR220305

(b) Explain the working of a bonded strain gauge accelerometer with neat sketch. [8+8] 7. (a) Name the different types of strain gauges used in practice and explain how the selection of a strain gauge affect the measurement of strain. (b) How resistive strain gauges are calibrated?

[8+8]

8. (a) Briefly explain the different types of control systems. (b) Describe the working of one automatic control system used in practice, outline functional elements of that system. [8+8] ⋆⋆⋆⋆⋆

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Set No. 3

Code No: RR220305

II B.Tech II Semester Regular Examinations, Apr/May 2006 INSTRUMENTATION AND CONTROL SYSTEMS ( Common to Mechanical Engineering, Production Engineering and Automobile Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. (a) Discuss about the time response of first order system for i. Impulse input ii. Step input iii. Ramp input (b) Explain in detail about following terms: i. ii. iii. iv.

Speed of response Measuring lag Fidelity Dynamic error

[16]

2. (a) Explain the concept of resistive transducer for measuring displacement. (b) What is variable capacitance device and explain how it is useful to measure displacement industrially? [16] 3. (a) What are the different types of materials commonly used in thermisters? (b) Give the various forms of thermisters. (c) Explain the temperature-resistance relation of NTC thermister. [4+4+8] 4. (a) Illustrate the bellows arrangement used to measure differential pressure. (b) List the gauges for the measurement of high and medium pressures. (c) Explain any one high pressure measuring device.

[8+4+4]

5. Explain the principle of operations of (a) Hot wire anemometer. (b) Turbine meter for the measurement of Fluid velocity.

[16]

6. (a) Explain how a vibrometer is calibrated to measure acceleration. (b) How is measurement of vibrations on large structures done? Explain the method in detail. [8+8] 7. (a) Describe the advantageous of semiconductor type strain gauge over the other types. 1 of 2

Set No. 3

Code No: RR220305

(b) Describe the salient features of a semiconductor type strain gauge. (c) Explain the factors affecting the strain measurement.

[4+4+8]

8. (a) Briefly explain the different types of control systems. (b) Describe the working of one automatic control system used in practice, outline functional elements of that system. [8+8] ⋆⋆⋆⋆⋆

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Set No. 4

Code No: RR220305

II B.Tech II Semester Regular Examinations, Apr/May 2006 INSTRUMENTATION AND CONTROL SYSTEMS ( Common to Mechanical Engineering, Production Engineering and Automobile Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ 1. Explain briefly about the types of errors involved in measurement systems by giving suitable examples. Discuss the means adopted to reduce these errors. [16] 2. (a) Explain the concept of resistive transducer for measuring displacement. (b) What is variable capacitance device and explain how it is useful to measure displacement industrially? [16] 3. What is thermocouple? With a neat sketch explain its construction, working principle and applications. [16] 4. (a) Differentiate between Atmospheric pressure and Gauge pressure and Vacuum. (b) With the aid of neat sketches, explain the principle of operation of various. [16] 5. Enumerate the principle of operation of the following (a) capacitative level indicator. (b) ultrasonic level measuring instrument.

[8+8]

6. (a) What are the advantages of piezoelectric type accelerometer? (b) Why vibrations has to be measured. How vibrations are measured? (c) What is a psychrometer? Explain the working of a psychrometer with neat sketch. [4+2+8] 7. (a) Explain the factors affecting the strain measurement. (b) Explain the working of servo accelerometer with neat sketch.

[8+8]

8. (a) Briefly explain the different types of control systems. (b) Describe the working of one automatic control system used in practice, outline functional elements of that system. [8+8] ⋆⋆⋆⋆⋆

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