Anna University Chennai 2005 B.E Electrical and Electronics Engineering Fifth Semester EE331 – Measurement & Instrumentation - Question Paper

B.E. Electrical and Electronics Engineering
Fifth Semester
EE331 – Measurement & Instrumentation
Time : three Hours Max Marks : 100
PART – A
ans All ques. (10 x two = 20 marks)
1. describe limiting errors? Derive the expression for relative limiting error?
2. describe linear time invariant and line time variant systems. provide examples.
3. Why PMMC ammeters are the most widely used instrument?
4. Draw the equivalent circuit and phasor diagram of a potential transformer.
5. List out the kinds of input circuits used in the signal conditioning.
6. describe (i) Differential mode gain (ii) Common mode rejection ratio.
7. provide the advantages and disadvantages of LCDS.
8. List out the basic components of a tape recorder.
9. An accelerometer has a seismic mass of 0.05kg and a spring constant of 3x103N/M.
Maximum mass displacement is ±0.02m. compute.
(i) Maximum measurable acceleration (ii) Natural frequency
10. List out the advantages and disadvantages of RTD.
PART – B
(5 x 16 = 80 Marks)
11.i) A set of independent ten measurement were made to determine the weight of a load
shot. The weights in gramme were 1.570, 1.597, 1.591, 1.562, 1.577, 1.580, 1.564,
1.586, 1.550, 1.575.
Determine
(i) Arithmetic mean
(ii) avg. deviation
(iii) Standard deviation
(iv) Variance
(v) Proable fault of 1 studying
(vi) Proable fault of the mean
ii) A measuring system has an exponential response to step input. The time constant of
the system is 2S. What is the time needed for reaching (i) 50% and (ii) 80% of final
steady state studying.
12.a) discuss in detail the effect of
(i) Opening the secondary circuit of a current transformer when primary winding
is energized?
(ii) With a neat sketch discuss the working of a 3F wattmeter.
OR
12.b)i) discuss the construction and working of Weston kind frequency meter.
ii) Design a multirange ammeter with range of 1A, 5A, 25A and 125A employing
individual shunts in every case. A d’ Arsonval movement with an internal resistance of
730O and full-scale current of 5mA is available.
13.a)i) discuss in detail the successive approximation method of A/D Conversation.
ii) discuss the operation of V/F converter.
OR
13.b)i) A thermistor of resistance 1000O at 50°C temp is connected in a bridge circuit having
all arms of resistance 1000O. The supply voltage to the bridge is 40V. The resistance
of the thermistor increases by 5O for a reduce of temp of 1°C. obtain the temp if the
open circuit voltage of the bridge is 50mv.
ii) discuss the operation of sample and hold circuit with suitable diagram.
14.a)i) Draw the block diagram of a digital CRO and discuss every block.
ii) The gap of reproducing head in a tape recorder is 6.4 µm. Determine the minimum
speed of the tape for satisfactory response at 50KHZ.
presume the wave length on the tap is greater than 2.5 times the gap length.
OR
14.b) discuss in detail the operation of any 2 digital printers.
15.a) Write short note on
i. Digital transducer
ii. Piezo electric transducer
OR
15.b)i) discuss the liquid level measurement using resistive method.
ii) define the method of measurement of differential pressure using inductive
transducer.
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Earning:   Approval pending.