Electrical Measurement & Instrumentation B.E Question Paper : jaduniv.edu.in
Name of the University : Jadavpur University
Department : Power Engineering
Degree : B.E
Subject Name : Electrical Measurement & Instrumentation
Year/Sem : III/III
Website : jaduniv.edu.in
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/dspace.jdvu.ac.in/5510-Elect.%20Meas.%20&%20Instrumentation.pdf
Electrical Measurement & Instrumentation Question Paper
Bachelor Of Power Engg, Examination, 2012 : (3Year,Sem)
Subject: Elect. Meas & Instrumentation
Part I :
Time : Three Hours (2 marks allotted for neatness)
Full Marks : 50
Related : Jadavpur University IC Engines & Gas Trubine B.E Question Paper : www.pdfquestion.in/5509.html
Answer any THREE questions :
1. a) Define: Accuracy, precision, sensitivity, loading effect, hysteresis effect. 10
b) Differentiate among different torques are activated for operation of electrical measuring instruments, 6
2.) Derive the governing equation of Dynamometer type wattmeter with a neat figure. 8
b)The spring constant of a 15 ADynamometer watmeter is 115-10°Nm per 8
radian. The variation of mutual inductance with angular position of moving system is practically linear over the operating range; the rate of change is being .085 mH per radian. If full scale deflection of instrument is 85 degrees, calculate the current required in voltage coil at full scale on dic circuit.
3.a)State the errors of rectifer type voltmeter & their compensation techniques. 6
b)State the advantages & limitations of electrostatic voltmeter. 4
c)The reading 150 volt of a 200 volt electrostatic voltmeter is to represent 15,000 volts when its range is extended by the use of a capacitor in series. If the capacitance of the voltmeter at the above reading is 90 upf, find the capacitance of the capacitor multiplier required. 6
4.) Draw neat circuit diagrams of induction type voltmeter, ammeter & wattmeter showing basic components. 6
b)From the basic deflecting torque expression of induction type instrument comment on maximum torque. 4
c)What are the sources of errors of Induction type watmeter & how can you rectify those errors? 6
5.a)State the operating principle of type Moving Iron frequency meter with a neat figure. 8
b)State the working principle of Electrodynamic Power factor meter with a neat figure 8
Bachelor of Power Engineering Year, 1Semester Examination, 2012 :
Electrical Measurement and Instrumentation :
(50 marks for each part)
Use separate AnswerScript for each part :
Time: Three Hours
Full Marks; 100
Part II :
Answer any three questions (2 marks for neatness)
I. (a)Describe the principle of operation of moving coil wibration galvanometer,
(b) Explain, how the amplitude of vibration of the same can be made large”
(c) The coil of a moving coil galvanometer is wound on a non-magnetic former whose height and width are both 2 cm. It moves in a constant field of .12 m. The moment of inertia of its moving parts is .-mand the control spring constant is 30x10Nmrad,
Calculate (i) the number of turns that must be wound on the coil to produce the deflection of 150° With a current of 10 mA and
(ii) the resistance of the coil to produce critical damping, all damping assumed to be electromagnetic.
2. A ring core current transformer with a nominal ratio of 5005 and a bar primary has secondary resistance of .5 and a negligible secondary reactance. The resultant of magnetizing and iron loss components of the primary current associated with full load secondary turrent of 5Ain a noninductive burden of 104) is 3 A at a power factor of 04. Calculate the true ratio and phase angle error of the CT on full load, Calculate also the total flux in the core assuming a frequency of 50 Hz. Derive the equations used to solve the problem. 16
3. a) How the unknown inductances are measured using Andersons bridge. What are the advantages of this bridge over the Maxwells bridge?
(b)A Schering bridge is used for measuring power loss in dielectrics. The specimens are in the form of .3 cm thick and have a dielectric constant of 23. The area of each electrode is 314 cmand the loss angle is known to be 9 for a frequency of 50 Hz. The fixed resistor is of 1000 and the fixed capacitor is 50 pF. Determine the Value of Variable capacitor and resistor, ,
4. a) Describe the method of calibrating a Wattmeter using Potentiometer.
(b)Four arms of a Wheatstone bridge are as follows
The galvanometer has a resistance of 100 , a sensitivity of 100 mm1A and is connected across and its deflection if the resistance of the arm DA is changed from 400 to 401 .
5. . Write shortnotes on any two of the following
(i) Measurement of low resistance,
ii) Sensitivity calculation of Galvánometer.
(iii) Coordinate type AC potentiometer.
(iv) Determination of BH curves and hysteresis loops in ferromagnetic ring specimen using Ballistic method.