Anna University Chennai 2009-4th Sem B.E Electronics & Tele-Communication Engineering /B.Tech , /E - Question Paper

EC 1255 - Measurements and Instrumentation

Part - A (10x2=20)

1. What is measurement and how is it classified?
2. Distinguish ranging from active and passive transducers.
3. List a few applications of CRO.
4. What is the basic principal behind the working of Q meter?
5. describe THD.
6. What is the need for multiple period measurement?
7. List various instruments used as signal analysers.
8. How is DVM classified?
9. List atleast four causes for power loss in fibre-optic cables
10. What is the need for multiplexing? How is it classified?

Part - B

11.a) (i) discuss the errors in measurement by giving the suitable examples. explain the means adopted to minimise the errors. (6)
(ii) elaborate the various effects used in producing deflecting torque in an analog instrument. Cite examples in which these effects are used. (10)
OR

b) define the working of Hay's bridge for measurement of Inductance. Derive the equations for balance and draw the phasor diagram under conditions of balance. Why is this bridge suited for measurement of inductance of high Q coils? (16)

12).a) (i) discuss with the help of a bloack diagram the different parts of an electronic multimeter (8)
(ii) define the principle of working and circuit diagram of a digital storage oscilloscope(8)

OR

b) define the following:
(i) Q-factor (5)
(ii) Inductance (5)
(iii)Effective resistance (6)

13.a) (i) Draw the block diagram of sweep generator covering the entire frequency band (8)
(ii) discuss the direct and indirect frequency synthesis (8)

OR

b) (i) define the functionning of a total harmonic distortion meter with a diagram (10)
(ii) define the engineering applications of wave analyser (6)

14.a) define with the help of suitable diagrams the subsequent kind of measurements using digital frequency meter: (4x4=16)
1) Time period measurement
2) Time Interval Measurement
3) Frequency measurement
4) Ratio of two frequencies

OR

b) discuss the subsequent DVM
(i) Ramp kind (8)
(ii) Integrating kind (8)

15.a) (i) What is data acquisition? elaborate the basic objectives of DAS? discuss briefly the difference ranging from analog and digital DAS? (8)
(ii) discuss the computer controlled testing system of an audio amplifier with suitable block diagrams (8)

OR

b) (i) elaborate the signal lines in IEEE488 bus and discuss in brief. (4)
(ii) Write short notes on(3x4=12)
a) Optical fiber sources
b) Optical fiber detectors
c) OTDR

Earning:   Approval pending.