Course: B.Tech (Semester V) Subject Code: KEC-057
Subject Name: Electronic Instrumentation & Measurements Time: 3 Hours
Total Marks: 100
Note: Attempt all sections. If any data is missing, assume suitably.
Section A – Short Answer Questions (2 × 10 = 20 Marks)
Answer all briefly:
Calculate the maximum percentage error in the difference of two measured voltages when V1=100±1%V_1 = 100 \pm 1\%V1=100±1% and V2=80±5%V_2 = 80 \pm 5\%V2=80±5%.
Define swamping resistance used in PMMC instruments.
What is calibration in measuring instruments?
Define 1:1 and 20:1 probes.
State the balance equation of Wheatstone bridge.
What is residual resistance and inductance in a Q-meter?
What is the role of time base circuit in a CRO?
Define interpolation in oscilloscope systems.
Define force transducer in measurement systems.
Draw the block diagram of a Data Acquisition System (DAS).
Section B – Descriptive Questions (10 × 3 = 30 Marks)
Attempt any three:
Explain DC ammeter and DC voltmeter in measurement systems.
Explain different types of digital multimeters with proper diagrams.
A Hay bridge operating at 100 Hz is balanced when
C3=0.1μF,R1=1.26kΩ,R3=65Ω,R4=600ΩC_3 = 0.1 \mu F, R_1 = 1.26 kΩ, R_3 = 65 Ω, R_4 = 600 ΩC3=0.1μF,R1=1.26kΩ,R3=65Ω,R4=600Ω.
→ Find inductance, resistance, and Q factor of the measured inductor.
Draw block diagram and waveform of a Digital Storage Oscilloscope (DSO) and explain its application.
Describe Hall-effect transducers and their applications.
Section C – Long Answer Questions (10 × 5 = 50 Marks)
Question 3
(a) Explain working principle of PMMC (Permanent Magnet Moving Coil) instrument using torque equation.
or
(b) Given readings: 41.7, 42.0, 41.7, 42.0, 42.1, 41.6, 42.0, 41.9, 42.5, 41.8
Calculate:
(i) Arithmetic mean (ii) Standard deviation
(iii) Probable error of one reading (iv) Probable error of mean
(v) Range
Question 4
(a) List and explain types of probes used in measurement with circuit diagrams.
or
(b) Explain AC electronic voltmeter circuits with diagrams.
Question 5
(a) Derive the Maxwell Bridge equation and solve for LLL, RRR, and Q factor when
C3=0.1μF,R1=1.26kΩ,R3=470Ω,R4=500Ω,f=100HzC_3 = 0.1 \mu F, R_1 = 1.26 kΩ, R_3 = 470 Ω, R_4 = 500 Ω, f = 100 HzC3=0.1μF,R1=1.26kΩ,R3=470Ω,R4=500Ω,f=100Hz.
or
(b) Explain Kelvin Double Bridge method for measuring low resistance and derive its balance condition.
Question 6
(a) Explain the working principle, block diagram, and waveform of a Sampling Oscilloscope.
or
(b) Draw and explain Dual Trace Oscilloscope with its block and waveform diagrams.
Question 7
(a) What is a Transducer? Explain types of transducers used in measurement.
or
(b) Explain Thermocouples and their types with applications.