Shivaji University 2008-4th Sem B.E Electrical Engineering S.E(Electrical) , Electrical Measurement - Question Paper

part - I:
1. a) describe 'standard'. provide it's classification and discuss international standards and primary standards.
b) 2 watt-meters are being used to measure power of a balanced load of 30A at power factor 0.8, lagging being supplied by a 3 phase 3 wire 440 V supply. compute power consumed, studying of wattmeter no. 1, studying of wattmeter no. 2.

2. a) discuss method for measurement of reactive power in 3 phase circuit.
b) A milliammeter of 2.5 ohms resistance reads upto 100 mA. compute the resistance which is necessary to enable to be used as: (i) A voltmeter studying reading uptp 10V, (ii) An ammeter studying upto 10A. Draw connection diagram in every case.

3. a) discuss construction and working of an electro-dynamometer kind of wattmeter.
b) discuss construction and working principle of repulsion kind of moving iron instrument. Draw neat diagram.

4. Write short note (any three):
a) Nadler Lipman power factor meter.
b) Synchronoscope
c) Damping of galvanometer
d) Errors of uncertainties in measuring instrument.


part - II:
5. a) elaborate the errors in energy meter and how they are compensated in induction kind energy meter?
b) Draw a block diagram of general purpose oscilloscope. discuss working of every block.

6. a) An A.C. energy meter is tested for half hour run at a supply voltage of 230 V and load current of 10 A at 0.8 lagging power factor. The redial studying at the begin 57.35 and at the end of the test was 58.25. The meter made 890 revolutions in 30 minutes run. Calculate: (i) fault in registration, (ii) fault in RPM of the meter.
b) With the help of block diagram discuss working of ramp kind DVM (Digital Voltmeter).

7. a) Draw a diagram and discuss working of Crompton's potentiometer.
b) The 4 arms of schering bridge are as follows:
Arm AB - Capacitor of 04 micro Farad in parallel with 1.5 kOhm resistance
Arm BC - Resistance of three kOhm
Arm CD - Unknown capacitor 'C' and 'R' in series
Arm DA - Capacitance of 0.4 micro Farad
Frequency one KHz, Determine the subsequent (i) R and C, (ii) Dissipation factor.

8. Write short note (any three).
a) Wein bridge
b) Application of CT and PT
c) Measurement of frequency using electronic counter.
d) Trivector meter

Earning:   Approval pending.