Subject: Electronic Measurements and Instrumentation (EEC403)
Exam Type: Theory
Semester: IV (4th Semester)
Session: 2016–17
Time: 3 Hours
Maximum Marks: 100
Section A – Short Answer Questions (10 × 2 = 20 Marks)
This section tests fundamental understanding of measurement concepts, instrument types, and signal characteristics.
Topics Covered:
Errors in Measurement: Random and gross errors – causes and distinction.
Accuracy vs. Precision: Difference in measurement quality and repeatability.
Dissipation & Quality Factor (Q): Concepts related to energy loss in reactive circuits.
Rise Time and Fall Time: Response characteristics of electronic signals.
Instrument Calibration: Procedure and importance of ensuring measurement accuracy.
True Value: Concept in metrology and its role in error analysis.
Johnson Noise & Shot Noise: Fundamental noise sources in electrical measurements.
Multimeter: Function, uses, and types (analog/digital).
Binder and Twister: Cable and wire connecting tools.
Transducer & Inverse Transducer: Definition and functional difference.
Section B – Descriptive / Analytical Questions (5 × 10 = 50 Marks)
This section emphasizes detailed descriptions and operational understanding of measurement instruments.
Key Questions Include: Electronic Voltmeter (Source Follower Type):
Working principle and circuit. Range extension method.
Use of zero adjustment and calibration resistors.
Piezoelectric Transducer:
Construction, modes of operation, and working principle with diagrams. Kelvin Double Bridge:
Explanation with circuit diagram for measuring low resistances accurately. PMMC Instrument:
Construction and operation. Mathematical proof showing linear scale behavior.
X–Y Recorder:
Working principle and block diagram. Explanation of plotting mechanism.
Plotter: Construction, working procedure, and typical applications.
Ammeter to Voltmeter Conversion: Method and necessary circuit modification.
Delay Line in Oscilloscope:
Reason for use in vertical section and detailed working principle.
Section C – Long Analytical / Application-Based Questions (2 × 15 = 30 Marks)
Questions Include:
Frequency Measurement using CRO:
Procedure for measuring signal frequency using time-base and waveform display.
Explanation of pulse distortion and attenuator probe with diagrams.
Measuring Instruments and Meters:
Working principles of:
Q-meter – measurement of inductance, capacitance, and Q-factor.
DC Ammeter and Voltmeter – construction and calibration.
Digital Frequency Meter System – block diagram and working.
Short Notes (Any Three):
Digital Storage Oscilloscope (DSO): Features, working, and applications.
Capacitance and Inductance Bridges: Principle and types.
Dual Trace Oscilloscope: Construction and applications in signal comparison.
Major Topics Covered
Measurement errors and calibration Analog and digital meters (PMMC, voltmeter, ammeter)
Oscilloscopes (CRO, DSO, dual-trace) Transducers (piezoelectric, inverse)
Measurement bridges (Kelvin, inductance, capacitance) Frequency measurement techniques
Plotters and recorders Noise in electronic measurement systems
Purpose of the Paper
This exam assesses both conceptual understanding and practical application of electronic measurement principles.
It aims to test how students apply theoretical knowledge to real-world instrumentation, emphasizing accuracy, calibration, and analysis of signals.
