Code: DE11              Subject: ELECTRONIC INSTRUMENTATION & MEASUREMENTS

Time: 3 Hours                                                                                                     Max. Marks: 100

NOTE: There are 9 Questions in all.

·  Question 1 is compulsory and carries 20 marks. Answer to Q. 1. must be written in the space provided for it in the answer book supplied and nowhere else.

·  Out of the remaining EIGHT Questions answer any FIVE Questions. Each question carries 16 marks.

·  Any required data not explicitly given, may be suitably assumed and stated.

Q.1       Choose the correct or best alternative in the following:                                         (2x10)

a. A reading is recorded as 23.60 V. The reading has

(A)  3 significant figures                        (B)  Five significant figures

(C)   Four significant figures                  (D)  None of above

b. A set of readings has narrow range and therefore it has

(A) low precision                                (B)  high precision

(C)  low accuracy                                (D)  high accuracy

             c.   Multirange ammeter uses

(A) Series shunt                                   (B) Universal shunt

(C) Parallel shunt                                 (D) All of above

             d.   The direction of horizontal sweep on CRO is

(A)  Up and down                              (B)  left and right

(C)  right and left                                 (D)  down and up

             e.   Digital instruments have input impedance of the order of

(A) ohms                                            (B)  Kilo ohms

(C)  mega ohms                                   (D)  milli ohms       

             f.    Spectrum analyser is used across the frequency spectrum of given signal to study

(A) Current distribution                       (B)  Voltage distribution

(C)  Power distribution                        (D)  Energy distribution

             g.   Harmonic distortion in amplifiers is caused by

(A) Presence of noise                         (B)  Positive feed back

(C)  Non-linear characteristics             (D) None of above

h.   The Q factor of coil at frequency 1.5 MHz of an RLC circuit is 150. The bandwidth is

(A) 225 MHz                                     (B) 10 KHz

(C) 1.06 MHz                                     (D) None of above

             i.    The capability of radio receiver to reject unwanted signals is

(A) Noise figure                                 (B) Selectivity

(C)  Sensitivity                                     (D) Image response

             j.    Piezo electric transducers are

(A)  Passive transducer                       (B) Active transducer

(C)  Inverse transducer                        (D) Both (B) and (C)

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

Q.2     a.   What are different types of errors in measurement? Explain each briefly.              (8)

             b.   Explain the working of ramp type digital voltmeter.                                              (8)

Q.3     a.   Explain how Schering bridge is used for measurement of capacitance.                 (8)

             b.   What is an audio frequency signal generator? Explain its working with the help of block diagram.                                                                (8)

Q.4     a.   With the help of block diagram, explain working of CRO.                                   (8)

b.   Describe briefly sampling oscilloscope. (8)

Q.5     a.   Explain the method of measurement of flux density.                                             (8)

b.   Explain the methods of measurement of RF power.                                             (8)

  Q.6     a. Explain briefly various receiver parameters.                                                        (8)

             b.   Draw the block diagram of wave analyser and explain its working.                      (8)

Q.7     a.   Draw the circuit of R-2R type D/A converter and explain its operation.               (8)

b.   Explain working of counter type A/D converter.                                                  (8)

Q.8     a.   Name two types of capacitive transducers and give the constructional features for one of them.                                                                  (8)

             b.   Differentiate between active and passive transducers.                                          (8)

  Q.9                                                                      Write short notes on any TWO of the following:

                    (i) Q-meter

                    (ii) Digital frequency counter

                    (iii) Standards                                                                                                (8x2)