EX-604-A Electronic Instrumentation - May 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 dual beam and sampling CRO with necessary sketches and diagrams.
   How to answer

   • Define dual-beam CRO with two electron guns / two traces
   • Define sampling CRO for high-frequency signals using sampling principle
   • Block diagrams and sketches of both
   • Comparison / applications
2. 7 Marks
   bDefine these terms:

   1. i)Graticule and Lissajous pattern
   2. ii)Q meter
   How to answer

   • Define graticule and Lissajous pattern with frequency/phase measurement use
   • Define Q-meter principle for Q-factor measurement
   • Relevant diagrams / formulas
   • Applications
3. 7 Marks
   aExplain the working of Schering Bridge with neat sketches. What are the special features of high voltage Schering Bridge?
   How to answer

   • Circuit diagram of Schering bridge with arms R, C
   • Balance conditions derivation
   • Phasor / neat sketches
   • Special features of high-voltage Schering bridge
4. 7 Marks
   bExplain why Maxwell inductance Capacitance Bridge is useful for measurement of inductance of coils having storage factor between 1 and 10.
   How to answer

   • Circuit of Maxwell inductance-capacitance bridge
   • Balance equations for L and Q
   • Why Q range 1 to 10 gives independent balance
   • Limitation for low/high Q coils
5. 7 Marks
   aAn electrically deflected CRT has a final anode voltage of $2000\,v$ and parallel deflecting plates $1.5\,cm$ along and $5\,mm$ apart. If the screen is $50\,cm$ from the center of deflecting plates. Find:

   1. i)beam speed
   2. ii)the deflection sensitivity of the tube
   3. iii)deflection factor of the tube
   How to answer

   • Beam velocity formula $v = \sqrt{2eV_a/m}$ and calculation
   • Deflection sensitivity $S = lL/2dV_a$ derivation and value
   • Deflection factor $G = 1/S$
   • Units in mm/V and V/mm
6. 7 Marks
   bDescribe the circuits and working of wave analysers used for audio frequency and megahertz ranges.
   How to answer

   • Need for wave analyser / frequency selective measurement
   • Circuit for audio-frequency analyser
   • Circuit for megahertz / heterodyne analyser
   • Working and applications
7. 7 Marks
   aExplain the following terms:

   1. i)Total harmonic distortion
   2. ii)Beat frequency oscillator
   How to answer

   • Definition and formula for total harmonic distortion
   • Definition and working of beat frequency oscillator
   • Block diagram
   • Use in distortion / signal generation
8. 7 Marks
   bWhat do you understand by function generator? Explain its working principle.
   How to answer

   • Definition of function generator
   • Block diagram / working principle
   • Generation of sine, square, triangular waves
   • Controls and applications
9. 7 Marks
   aFor a transducer describe the followings:

   1. i)primary and secondary Transducer
   2. ii)input characteristics.
   How to answer

   • Definition of primary vs secondary transducer with examples
   • Meaning of input characteristics
   • Classification diagram
   • Selection criteria
10. 7 Marks
    bDescribe the different modes of operation of piezo-electric transducers. Also explain the application of Piezo-electric transducers.
    How to answer

    • Piezoelectric effect principle
    • Different modes: longitudinal, transverse, shear
    • Construction / diagrams
    • Applications in pressure, vibration, ultrasonic
11. 7 Marks
    aDescribe the method for measurement of temperature with the use of

    1. i)RTD
    2. ii)Thermistors
    How to answer

    • Principle of RTD with resistance-temperature relation
    • Principle of thermistor with characteristics
    • Measurement circuits / bridges
    • Comparison and uses
12. 7 Marks
    bExplain working principle of strain gauge also define the expression for gauge factor.
    How to answer

    • Working principle of strain gauge: resistance change with strain
    • Derivation of gauge factor $G_f = (\Delta R/R)/(\Delta L/L)$
    • Types / bridge measurement setup
    • Applications
13. 7 Marks
    aExplain the IEEE 488 instrumentation bus with the help of necessary schematic diagram.
    How to answer

    • Purpose of IEEE 488 GPIB interface
    • Schematic / bus lines: data, handshake, management
    • Talker-listener-controller operation
    • Interconnection diagram
14. 7 Marks
    bDiscuss in detail about the AF Sine and square wave generator.
    How to answer

    • Circuit of AF sine generator
    • Circuit of square wave generator
    • Working with waveforms
    • Frequency ranges and uses
15. 7 Marks
    aDefine these terms:

    1. i)LED
    2. ii)DVM
    How to answer

    • Define LED principle and use as indicator/display
    • Define DVM principle and types
    • Block diagram basics
    • Instrumentation applications
16. 7 Marks
    bWhat is XY recorder? Explain with suitable circuit diagram, the working of an XY recorder and also write its applications.
    How to answer

    • Definition of XY recorder
    • Suitable circuit / block diagram with X-Y servos
    • Working steps for tracing two inputs
    • Applications in plotting characteristics