Gujarat Technological University 2009-1st Sem Diploma Electrical Engineering (DEE) in electrical subject-electrical instrumentation - Question Paper

MAY/JUNE 2009

1. (a) a actual value of 95 volt when measured by a voltmeter of range 300 v is indicated as 100 v.find percentage accuracy base on (a) scale studying and (b) full scale [marks 5]
OR
(a) obtain the resolution in a voltmeter with uniform scale having 25 divisions.the full scale deflection is 100 v.it is possible to estimating studying with half a division. [marks 5]
(b) draw a block diagram of typical instrumentation system and discuss function of every block.
2. ans any four: [marks 20]
(a) discuss principle of potentiometer.
(b) with circuit diagram discuss 3 dial potentiometer.
(c) draw schematic diagram of kelvin double bridge and find relation for determine value of unknown resistance.
(d) discuss self balancing D.C Wheatstone bridge for temperature measurement.
(e) draw front panel layout of universal impedance bridge and discuss every control.
(f) discuss wein's bridge for measurement of unknown frequency .
3. ans any five: [marks 25]
(a) state the advantages of trivector meter.
(b) list out advantages and disadvantages of dynamo meter kind meter.
(c) discuss 3 element kind 3 phase meter waltmeter.
(d) classify electromechanical instruments.
(e) compare gravity control and spring control.
(f) discuss fault take place in energy meter .
(g) discuss 2 methods of measuring pressure.
4.answer any 4 : [marks 20]
(a) draw block diagram of DVM and discuss it's working.
(b) compare ranging from analog and digital instruments.
(c) draw and discuss block diagram of C.R.O.
(d) draw and discuss basic FET voltmeter ckt.
(e) advantages of TVT/FET voltmeter.
(f) discuss working of synch trans meter.
5.answer any three: [MARKS 15]
(a) discuss IS procedure for calibration of voltmeter.
(b) discuss IS procedure for calibration of ammeter.
(c) discuss different adjustment of energy meter.
(d) list out general test condition as per IS for calibration of ammeter,volt meter and watt meter.
(e) state 6 application of micro-processor.
6. ans any 2 : [MARKS 10]
(a) discuss how megger is used to measure the insulation resistance of cable.
(b) for measurement of 3 phase power.draw circuits diagram of 2 watt meter method.
(c) discuss method of measurement of reactive power in 3 phase ckt.
(d) state the advantages of lamed digital control.

Earning:   Approval pending.