EC-302 Electronic Measurements and Instrumentation - Nov 2022 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 the following terms in detail

   1. i)Accuracy
   2. ii)Resolution
   3. iii)Precision
   4. iv)Expected value
   How to answer

   • Define Accuracy as closeness to true value
   • Define Precision as repeatability / closeness among readings
   • Define Resolution as smallest increment detectable
   • Define Expected value as mean / anticipated value
2. 7 Marks
   bList out different AC voltmeters and explain the working of any one voltmeter in detail.
   How to answer

   • List types of AC voltmeters - average, peak, true RMS, etc.
   • Select any one type for detailed explanation
   • Explain block diagram / circuit and working
   • Mention applications / characteristics
3. 7 Marks
   aExplain the concept of storage oscilloscope along with circuit diagram.
   How to answer

   • Define storage oscilloscope and need for storage
   • Explain storage CRT principle - mesh storage, phosphor persistence
   • Present circuit / block diagram
   • Mention types and applications
4. 7 Marks
   bDraw the circuit diagram of Sampling oscilloscope and explain its operation in detail.
   How to answer

   • Present circuit / block diagram of sampling oscilloscope
   • Explain sampling gate, staircase and delay operation
   • Explain reconstruction of high-frequency waveform
   • Mention applications for very high frequency
5. 7 Marks
   aDraw the circuit diagram of Schering's Bridge and explains the operation of it.
   How to answer

   • Draw Schering's Bridge with standard capacitor, arms and detector
   • Write balance conditions
   • Explain measurement of capacitance and dissipation factor
   • Mention high-voltage insulation testing use
6. 7 Marks
   bExplain the "parallel-connection" method of using Q-meter and Obtain the expressions for resistance, reactance and Q-factor.
   How to answer

   • Describe parallel-connection method of Q-meter
   • Draw connection of unknown impedance in parallel
   • Derive expressions for resistance, reactance
   • Derive expression for Q-factor
7. 7 Marks
   aWhat is Thermistor and explain its importance along with advantages of it.
   How to answer

   • Define thermistor and its types NTC/PTC
   • Explain resistance-temperature characteristics
   • Explain importance in temperature measurement
   • List advantages like sensitivity, size, cost
8. 7 Marks
   bDraw the Linear variable differential Transducer and explain its operation in detail.
   How to answer

   • Draw LVDT construction with primary, secondaries and core
   • Explain differential output vs core displacement
   • Explain phase and magnitude variation
   • Mention applications and advantages
9. 7 Marks
   aDraw the block diagram of 3-bit R-2R ladder DAC and explain its operation.
   How to answer

   • Draw 3-bit R-2R ladder with R-2R network and op-amp
   • Explain binary-weighted current division
   • Derive output voltage expression
   • Mention advantages over weighted resistor
10. 7 Marks
    bWrite and explain the total number of clock pulses needed for counter type, flash, SAR, and dual slope ADC's.
    How to answer

    • State clock pulses for flash, counter, SAR, dual-slope ADCs
    • Explain reasoning - $2^n$, $n$, $2^{n+1}$ etc.
    • Compare conversion speed vs complexity
    • Summarize in table
11. 7 Marks
    aExplain the working principle of successive approximation A/D conversion with suitable diagram.
    How to answer

    • Draw block diagram with DAC, comparator, SAR register
    • Explain successive bit trial from MSB to LSB
    • Explain conversion steps with example
    • Mention conversion time of n clocks
12. 7 Marks
    bExplain the 4-bit weighted resistor type D/A converter in detail.
    How to answer

    • Draw 4-bit weighted resistor network with op-amp summer
    • Explain binary-weighted currents
    • Derive analog output expression
    • Mention disadvantages like resistor range
13. 7 Marks
    aWhat is the difference between photo-emissive, photo-conductive and photo voltaic transducers?
    How to answer

    • Define photo-emissive, photo-conductive, photovoltaic effects
    • Compare construction and working principle
    • Compare characteristics and examples
    • Mention applications of each
14. 7 Marks
    bDraw the circuit diagram of Dual Trace oscilloscope and explain its operation in detail.
    How to answer

    • Draw circuit / block of dual trace oscilloscope with two channels
    • Explain alternate and chopped modes
    • Explain triggering and display operation
    • Mention comparison with dual beam
15. 14 Marks
    Write a short note on any two.

    1. a)Accelerometer
    2. b)Bolometer
    3. c)Photo transistor
    4. d)Binary adder
    How to answer

    • Select any two devices from list
    • Explain construction / principle of each
    • Explain working with diagram
    • Mention applications