4.
Attempt any two parts of the following :
(a)
(10×2=20)
EEC403
Printed Pages—4
Sketch the neat diagram of CRO. What is the utility of
(Following Paper ID and Roll No. to be filled in your Answer Book)
delay line and trigger circuit. Which part of CRT is known
PAPER ID : 0323
Roll No.
as electrostatic focusing system ? How the intensity to be
B. Tech.
(SEM. IV) THEORY EXAMINATION 2011-12
ELECTRONIC INSTRUMENTATION AND
MEASUREMENTS
controlled ? What is normal pressure of CRT ?
(b)
Find out the fy/fx of the following Lissajous pattern.
Assuming that 2 signal having frequencies fy and fx
respectively applied on Y-Y and X-X deflection plates.
(i)
(ii)
Time : 3 Hours
Note : (1)
(2)
(3)
(iii)
(iv)
1.
(v)
(c)
Sketch circuit to show how ac voltmeter and ammeter
should be calibrated using standard instruments. Explain.
5.
Attempt any two parts of the following :
(a)
(10×2=20)
Sketch a circuit to show how a potentiometer should be
used for calibrating a dc ammeter. Briefly explain.
(b)
Sketch the basic construction of a pen type galvanometer
strip chart recorder. Briefly explain the instrument
operation.
(c)
Explain the basic principle of sweep generator. Also draw
the block diagram of vertical amplifier.
EEC403/PUR-40807(Re)
4
475
Total Marks : 100
Attempt all questions.
Assume the missing data if any.
Marks are indicated at the end of each section.
Attempt any four parts of the following :
(5×4=20)
(a) What do you mean by instrumentation system ? Also
explain the functional block diagram of a measurement.
(b) Define fundamental and derived units. Derive the
relationship between electromagnetic system and
electrostatic system of the light velocity.
(c) Energy stored in a parallel plate capacitor per unit volume
(energy density) is given by w = k∈avbdc
∈ → permittivity of medium, d → distance between plates
v → voltage between plates, k → constant.
(d) Explain the limiting error in terms of true value. Two
capacitors C1 = 150 ± 2.4 µF, C2 = 120 ± 1.5 µF connected
in parallel, what is the limiting error of the resultant
capacitance C ?
(e) Describe the principle of operation, advantages,
disadvantages and application of PMMC.
(f) A PMMC instrument with FSD of 100 µA and a coil
resistance of 1 kΩ is to be converted into a voltmeter.
Determine the required multiplier resistance if the
voltmeter is to measure 50 V at full scale. Also calculate
the applied voltage when instrument indicates 0.8, 0.5 and
0.2 of FSD.
EEC403/PUR-40807(Re)
1
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Attempt any two parts of the following :
(a)
(10×2=20)
(d)
Describe the emitter follower voltmeter. The simple
emitter follower voltmeter has VCC = 20 V, Rs + Rm = 9.3 kΩ,
Im = 1 mA at full scale and transistor hFE = 100.
(i)
(e)
Calculate the meter current when E = 10 V.
(ii) Determine the voltmeter input resistance with and
Explain the sources of error in a Wheatstone bridge used
to measure very low resistance. Discuss the range of
resistance measurement with a Wheatstone bridge.
A 4-terminal resistor with a nominal resistance of 0.025 Ω
is to be measured on a Kelvin Bridge as shown in figure.
A 0.01 Ω standard resistor is available. Determine the
required ratio of R/P and r/p.
without the transistor.
(b)
R
Discuss the procedure for using the electronic voltmeter
G
P
–
for ac measurement.
(c)
i1
i1
Calculate the resistance scale marking at 25% and 75%
of full scale for the series ohmmeter in given figure.
i2
Four terminal
resistor
10
+
2.
i2
p
r
I
100 kΩ
I
S
Q
A
Four terminal
resistor
I + i1
E
1 kΩ
Eg
RX V
100 Ω
1.5 V
Electronic
Voltmeter
(f)
An op-amp voltmeter shown in figure, is required to
measure a maximum input of 20 mV. The op-amp input
current is 0.2 µA and the meter circuit has Im = 100 µA
10 Ω
FSD and Rm = 10 kΩ. Determine suitable resistance value
for R3 and R4.
3.
Attempt any four parts of the following :
(a)
(5×4=20)
Describe the various methods of measurement of medium
E
resistance.
(b)
+
–
Describe the operation and phasor diagram of Schering
–VEE
Bridge.
I4 R4 Vout
IB
Explain the converging balance equation of AC Bridge
↑
(c)
+VCC
IB
R3
when impedances in its phase magnitude form.
EEC403/PUR-40807(Re)
2
EEC403/PUR-40807(Re)
3
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