ME-402 Instrumentation and Control - Nov 2023 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aExplain different types of instruments with diagrams.
   How to answer

   • Define measurement instruments and classification - absolute/secondary, indicating/recording/integrating, active/passive, analog/digital
   • Explain each type with principle and example
   • Provide neat labelled diagrams for each type
2. 7 Marks
   bDraw a Block diagram of Generalised Mechanical System and explain its components.
   How to answer

   • Draw generalized block diagram: sensed medium, primary sensing element, variable conversion, manipulation, data transmission, presentation
   • Explain function of each block with example
   • Show signal flow from measurand to readout
3. 14 Marks
   Discuss the following :

   1. i)Measuring lag
   2. ii)Speed of response
   3. iii)Calibration
   4. iv)Types of errors
   How to answer

   • Define measuring lag, speed of response, calibration, errors
   • Explain dynamic vs static characteristics for each
   • Give examples and significance in instrumentation
4. 7 Marks
   aState and prove the linear property of Fourier Transform.
   How to answer

   • State linearity: Fourier transform of linear combination equals linear combination of transforms
   • Write mathematical statement $F\{a f_1 + b f_2\}=aF_1+bF_2$
   • Prove using integral definition of Fourier transform
5. 7 Marks
   bExplain briefly about Transient response in control system with diagram.
   How to answer

   • Define transient response and steady state
   • Explain parameters: delay, rise time, peak time, overshoot, settling time
   • Sketch typical underdamped step response with labels
6. 7 Marks
   aA bimetal strip is constructed of strips of yellow brass and bronze bonded together at 30 degree Celsius. Each has a thickness of 0.3 mm. Calculate the temperature which produces a radius of curvature of 0.132 m.
   How to answer

   • Write bimetallic strip curvature formula relating radius to differential thermal expansion
   • Substitute thickness $0.3$ mm each, $R=0.132$ m, brass/bronze expansion coefficients
   • Solve for temperature rise above $30^{\circ}C$
7. 7 Marks
   bExplain the working principle of RTD with neat diagram and give its applications.
   How to answer

   • State RTD principle: resistance of metal varies with temperature
   • Draw construction with platinum wire, sheath, leads and bridge circuit
   • List applications in temperature measurement and control
8. 7 Marks
   aExplain with a neat sketch, the working of a Dead weight pressure gauge. What are its advantages and limitations?
   How to answer

   • Draw dead weight tester with piston, cylinder, weights, pressure connection
   • Explain pressure balance $p = W/A$ principle and operation steps
   • List advantages (accuracy, calibration standard) and limitations (bulky, static, costly)
9. 7 Marks
   bDescribe Diaphragm pressure gauge with a neat sketch.
   How to answer

   • Draw diaphragm housing, diaphragm deflection and linkage to pointer
   • Explain pressure to displacement conversion
   • Mention uses for low pressure measurement
10. 7 Marks
    aExplain briefly about Ionisation transducer with diagram.
    How to answer

    • Define ionisation transducer principle
    • Draw vacuum tube / ionisation chamber diagram
    • Explain pressure/displacement to ion current conversion
11. 7 Marks
    bAn Electrical Resistance Strain gauge of 100 ohm resistance and gauge factor 2 is bonded to a specimen of steel. Calculate the change in resistance of the gauge when a tensile stress of 60 MN/sq.m is applied on the specimen.
    How to answer

    • Write gauge factor relation $G_f = (\Delta R/R)/\epsilon$ and Hooke's law $\sigma = E \epsilon$
    • Calculate strain from $60$ MN/sq.m stress using $E$ for steel and then $\Delta R$
    • Obtain change in resistance value in ohm
12. 7 Marks
    aDescribe the concept of Open loop system with Block Diagram. Differentiate the open loop system with closed loop system.
    How to answer

    • Define open loop system with block diagram and example
    • Explain components: controller, process, no feedback
    • Compare open vs closed loop on feedback, accuracy, stability, cost in table
13. 7 Marks
    bA constant water level is to be maintained in a boiler. Suggest a suitable automatic level control system with a block diagram and explain its working.
    How to answer

    • Suggest float / electrode based automatic level control with feedback
    • Draw block diagram: level sensor, controller, feed valve, boiler
    • Explain working maintaining constant water level
14. 14 Marks
    Write a short note on any two of the following:

    1. a)Manometer
    2. b)Stroboscope
    3. c)Orificemeter
    4. d)Load cell
    How to answer

    • Select any two devices from list
    • Explain principle, construction with sketch and working
    • Mention applications and limitations