QUESTION BANK FOR MID-II (3RD SEM, SUBJECT: EEMI

Question Bank (EEMI, 3RD SEM)
Subject Code:	2130903
Question No.	Question
	Chapter 1: Phylosophy of measurement
1	List the static charecteristics of an instrument.
2	Classify meters according to principle of operation.
3	State the advantages of digital instruments over analog instruments.
4	Explain following terms  with reference to instrument (1) Accuracy (2) Precision (3) drift (4) repeatability (5) sensitivity (6) Linearity (7) Hysteresis
5	State the various types of errors in an instrument. What do you mean by calibration of an instrument?
6	Explain following terms with reference to instrument (1) Re producibility (2) dead zone (3) Resolution (4) stability
7	What are the dynamic errors in an instruments
8	What do you mean by standards in measurement ?  Explain the types of standards.
	Chapter 2: Analog measurement of Electrical quantities
9	Classify the instruments based on their function.
10	Write the principle of moving coil instruments. Also state its advantages and disadvantages.
11	Explain briefly about PMMC and PMMI instruments with Torque equation.
12	A moving coil instrument whose resistance is 25 Ω gives full scale deflection with a current of 1 mA. This instrument is used with a manganin shunt to extend its range to 100 mA. Calculate the error caused by a 100  C  rise in a Temperature when: (1) copper moving coil is directly connected across manganin shunt (2) A 75 Ω manganin resistance is used in series with the instrument moving coil. Temperature co-efficient of copper is 0.0004 /0C and that of manganin is 0.00015/ 0C .
13	A moving coil instrument gives full scale deflection  of 10 mA when a potential difference across its terminal is 100 mV. Calculate (1) the shunt resistance for full scale deflection of 100 A. (2) series residtance for full scale reading with 1000 V.
14	Derive the torque equation of Dynamometer type instrument for D.C and A.C current measurements.
15	For a certain dynamometer type ammeter mutual inductance M varies with deflection in degrees as M= -6 cos (Ѳ+ 300) mH.  Find the deflection torque produced by a direct current of 50 mA corresponding to a deflection of 600.
16	Draw the different circuit diagrams for current and voltage measurement in Dynamometer type instruments.
17	List out the various sources of errors in Electrodynamometer type wattmeters.
18	Two wattmeters are connected to measure input to a balanced three phase circuit indicate 2000 W and 500 W respectively. Find power factor of circuit when (1) both the readings are same (2) when later reading is obtained after reversing the connections to the current coil of first instrument.
19	A wattmeter has a current coil of 0.1 Ω resistance and a pressure coil of 6500 Ω resistance. Calculate percentage errors, due to resistance when pressure coil is connected on (1) supply side (2) Load side.
20	Derive the torque equation of Electrostatic Instrument.
21	An Electrostatic voltmeter reading up to 2000V is controlled by a sping with a torsion constant of 5*10-6 Nm.rad has a full scale deflection of 900 Capacitance at zero voltage is 15 pF. What will be the  the capacitance when pointer will move to 2000 V. ?
22	Explain two wattmeter method used to measure power of a 3-phase balanced load.
23	Derive the Torque Equation for Energy Meter and mention what are errors occurred in the Energy Meter.
24	What are the various sources of error for Induction type energy meter? How can one overcome those errors?
25	Define phantom loading.
26	5 A  , 230 V meter on full load unity power factor test makes 60 revolutions in  360 seconds. If the normal disc speed is 520 revolution per KWh, what is the percentage error?
27	If an energy meter disc makes 10 revolutions in 100 seconds when a load of 450 Watt is connected to it, Find the meter constant in rev/KWH.
28	Explain with suitable example that why voltmeter with higher sensitivity is essential for better acuracy in measurement?
29	Explain How Instrument transformers can be used for extension of range of an Instrument?
30	Explain briefly about CT and PT with relevant Diagrams.
31	With an example explain the concept of burden on CT.
32	Explain about various errors in CT.
33	A 500 A/ 5 A, 50 Hz current transformer has a  bar primary. The secondary has burden is  a pure resistance of 1 Ω and it draws a curren of 5 A. If magnetic core requires 250 AT for magnetization, what will be the percentage ratio error?
34	Explain about westen type frequency meter.
35	Explain Rectifier type instrument working and its application.
36	Draw neat sketch of single phase electrodynamometer type power factor meter. Explain its working.
	Chapter 3: Measurement of Parameters
37	Derive the Generalized Equation for A.C Bridges at Balance Condition.
38	State the applications of whestons bridge.
39	Explain about Maxwell Bridge and Hay's Bridge.
40	classify the resistance based on the range of the Measurement.
41	What are the methods can be used for the Measurement of Low resistance
42	explain briefly about Kelvin bridge and Kelvin Double Bridge witth relevant diagram and equation.
43	What are the prectical difficulties in measurement of High resistance?
44	What are the methods can be used for measurement of  High resistance?
45	Explain briefly about application and importance of Megger and Eart tester for Earth Resistance measurement.
46	Describe working of low voltage schering bridge. State is practical application.
47	Wein bridge has the following specifications.  arm ab: A resistance of 200 Ω in parrallel with a capacitance of 1 µF. arm bc: A resistance of 400 Ω. arm cd: A resistance of 1000 Ω.  arm da :  A resistance of R2 in series with a capacitance of 2 µF. Determine R2 and frequency at which bridge will balance.
48	Write short note on Desaunty's bridge.
49	Explain Anderson's bridge with vector diagram.
50	what are the application of Maxwell's and Hay's Bridge ?