Electronic Instruments and Measurements - Dec 2012

Electronics Engineering (Semester 3)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

Answer any four :-

1 (a) Define sensitivity of an analog instrument. For PMMC instrument with FSD=100 mA find sensitivity(5 marks) 1 (b) What is Megger? Explain its working(5 marks) 1 (c) For ADC define resolution. Give suitable example(5 marks) 1 (d) Explain the working principle of DC Motor(5 marks) 1 (e) Explain the function of delay line in oscilloscope. What are the types of delay lines?(5 marks) 2 (a) What is intensity modulation? For what it is used? Can phase and frequency be measured using intensity modualtion?(10 marks) 2 (b) What is Q meter? Explain any one of the types of Q meter with the help of circuit diagram(10 marks) 3 (a) Draw and explain Kelvin's Bridge(10 marks) 3 (b) Explain the operating principle of 3-phase induction motor(10 marks) 4 (a) Draw and explain the block diagram of digital storage oscilloscope(10 marks) 4 (b) Explain R-2R ladder techniques of digital to analog converter(10 marks) 5 (a) Draw and explain any one of the types of electronic voltmeter. State its two advantages over analog voltmeter(10 marks) 5 (b) Explain digital phase meter using flip flop. Draw relevant waveforms at each point in a block diagram to illustrate(10 marks) 6 (a) Explain Schering bridge for measurement of capacitance. Derive the equation of unknown capacitance at balanced condition(10 marks) 6 (b) What is energy meter? Draw its constructional view and explain(10 marks)

Write short notes on (any two) :-

7 (a) Variable reluctance stepper motor(10 marks) 7 (b) A.F. signal generator (10 marks) 7 (c) Digital frequency meter(10 marks)