Important RGPV Question
EX-303 (Electrical Measurements and Instruments)
III Sem, EX
UNIT-1 : Measurement Systems & Galvanometers
Q.1) Enumerate the dynamic characteristics of a measuring system.
(RGPV JUNE 2023)
Q.2) Two resistors have the following ratings.
Determine the magnitude of resultant resistance and the limiting errors in percentage and in ohm if the above resistances are coected in Series and Parallel.
(RGPV JUNE 2023)
Q.3) Describe the construction and working of a ballistic galvanometer. Explain the difference in constructional details of a ballistic galvanometer and a d’Arsonval galvanometer.
(RGPV JUNE 2023)
Q.4) When a current of 0.001A is passed through a ballistic galvanometer, it gives a steady deflection of 50 scale divisions. When a capacitor charged to a potential of 100V d.c is discharged through the galvanometer, it gives a maximum throw of 220 scale divisions. The periodic time of swing is 4 second. Find the value of capacitance. The value of logarithmic decrement is 0.2.
(RGPV JUNE 2023)
Q.5) What do you understand by digital instruments? Explain with the help of a block diagram.
(RGPV JUNE 2020)
Q.6) Explain the construction and working of a D’Arsonval galvanometer with a neat sketch.
(RGPV JUNE 2020)
Q.7) Discuss various types of errors occurring in electrical measurements.
(RGPV JUNE 2020)
Q.8) What are the modifications in design for reduction of errors in potential transform which lead to smaller total errors?
(RGPV DEC 2020)
Q.9) Discuss static and dynamic characteristics of measurement systems.
(RGPV DEC 2020)
Q.10) What is the difference between accuracy and precision of a measuring instruments.
(RGPV NOV 2019)
Q.11) Write down the principle of operation and construction of ballistic galvanometer.
(RGPV NOV 2019)
Q.12) Describe the series and shunt type ohmmeter.
(RGPV NOV 2019)
Q.13) What is the loading effects due to shunt coected instruments?
(RGPV NOV 2019)
UNIT-2 : Different types of Ammeter & Voltmeter
Q.1) A moving coil meter gives full scale deflection with a current of 5mA, if the coil of the instrument has a resistance of 102 Ω. Show how it can be adopted to work i) as an ammeter with a range of 0 to 10 A.
(RGPV JUNE 2023)
Q.2) A multimeter having a sensitivity of 200052/V is used for the measurement of voltage across a circuit having an output resistance of 1052. The open circuit voltage is 6V. Find the reading of the multimeter when it is set to its 10V scale. Find the percentage error.
(RGPV JUNE 2023)
Q.3) Write down the working of electrodynamometer
(RGPV JUNE 2020)
Q.4) Describe the construction and working of a two element induction type energy meter.
(RGPV JUNE 2020)
Q.5) Write down the expression for control and deflection torque also discuss their advantages and disadvantages.
(RGPV DEC 2020)
Q.6) A moving coil voltmeter has a uniform scale with 100 divisions, scale full reading is 200 volt and 1/10 of a scale division can be estimated with a fair degree of certainty. Determine the resolution of instrument in volt.
(RGPV DEC 2020)
Q.7) Write down the expression for control and deflection. torque also discuss their advantages and disadvantages.
(RGPV NOV 2019,NOV 2018)
Q.8) Explain the different types of errors in measurement
(RGPV NOV 2019)
Q.9) What do you understand by PMMC also discuss its working.
(RGPV NOV 2019)
Q.10) A voltmeter having sensitivity of 20ks/V reads 220V on a 240V scale. When coected across an unknown resistor. The current through the resistor 4 mA. Calculate the percentage of error due to loading effect.
(RGPV NOV 2019)
Q.11) What is electro dynamometer wattmeter? Discuss the working and construction.
(RGPV NOV 2019)
Q.12) Explain the working principle of digital voltmeter.
(RGPV NOV 2019)
Q.13) Describe the construction detail and working of single phase induction type energy meter.
(RGPV NOV 2018)
Q.14) Describe the errors in electrodynamometer type wattmeter’s. Also explain their remedial solutions.
(RGPV NOV 2018)
UNIT-3 : Instrument Transformers, Measurement Of Power
Q.1) Draw the equivalent circuit and phasor diagram of a potential transformer. Derive the expression for its ratio and phase angle errors.
(RGPV JUNE 2023)
Q.2) A potential transformer with ratio 1000/100 V, has the following constants) Primary resistance 94.552, Secondary resistance 0.8652, Primary reactance 66.252, Total equivalent reactance 1102. Magnetizing current 0.02A at 0.4 pf.
Calculate i) The phase-angle error at no-load between primary and secondary voltages
ii) The load in VA at unity pf at which the phase angle will be zero.
(RGPV JUNE 2023)
Q.3) Describe the construction and working principle of single phase wattmeter.
(RGPV JUNE 2023)
Q.4) A 240V, 5 A, single phase energy meter has a registration constant of 1200 revolutions per kWh. It is tested by means of a 240V, 5A wattmeter having 500 scale divisions which can be read to 0.1 division and a stop watch which can be read to 0.01 second and which has negligible error. When tested at full load the meter makes 40 revolutions in 99.8s. If the human error in timing be taken as + 0.05s, estimate the limits within which the error of the meter may lie. The wattmeter is accurate to within 0.05 percent of its full scale reading.
(RGPV JUNE 2023)
Q.5) Explain how transformer steel available in strips of 25 cm length and 5 cm width is tested for iron losses by the wattmeter method.
(RGPV JUNE 2023)
Q.6) Compare Current Transformer with Potential Transformer.
(RGPV JUNE 2020)
Q.7) Discuss the absolute null method of testing of potential transformer.
(RGPV JUNE 2020, NOV 2019)
Q.8) With the help of neat experimental set up explain how 3 phase power is measured using 2 wattmeter method.
(RGPV JUNE 2020)
Q.9) Power measurement by using of CT’s and PT’s also discuss about the power measurement in three phase.
(RGPV DEC 2020)
Q.10) Measurement of power in three-phase circuit.
(RGPV DEC 2020)
Q.11) How to test the instrument transformers?
(RGPV DEC 2020)
Q.12) Write down the characteristics of potential transformers in detail.
(RGPV DEC 2020)
Q.13) What is a low power factor wattmeter? Explain its working and construction detail.
(RGPV DEC 2020)
Q.14) Describe the construction detail and working of an electrodynamometer type instrument.
(RGPV NOV 2019)
Q.15) How many wattmeters are used for measuring power in 3 phase four wire circuit?
(RGPV NOV 2018)
Q.16) What is a low power factor wattmeter? Explain its working and construction detail..
(RGPV NOV 2018)
Q.17) Explain the different advantages of instrument transformer.
(RGPV NOV 2018)
UNIT-4 : Measurement of Energy
Q.1) Explain construction and working principle of trivector meter
(RGPV JUNE 2020)
Q.2) What do you understand by tri-vector meter?
(RGPV DEC 2020)
Q.3) How we perform error-testing by use of Phantom loading?
(RGPV DEC 2020)
Q.4) What is hot wire instrument? Explain with suitable circuit.
(RGPV NOV 2018)
Q.5) What do you mean by tri-vector meter? Explain its construction and its working.
(RGPV NOV 2018)
UNIT-5 : Power Factor Meter, Frequency
Q.1) Explain the constructional features & principle of operation of moving iron instruments.
(RGPV JUNE 2023)
Q.2) Explain why Kelvin’s double bridge is superior to Wheatstone bridge for the purpose of low resistance measurement. Give theory of the bridge and necessary arrangement in order that greatest precision possible may be obtained.
(RGPV JUNE 2023)
Q.3) Describe the method for measurement of B-H curve of a magnetic material of bar form.
(RGPV JUNE 2023)
Q.4) What do you understand by hysteresis and loading effect?
(RGPV JUNE 2020)
Q.5) Describe the construction and working of 3-phase alternating field power factor meter.
(RGPV JUNE 2020)
Q.6) Explain the construction and working of a Weston type Synchroscope.
(RGPV JUNE 2020)
Q.7) How the resistance is classified under low, medium and high resistance? Suggest suitable methods for measuring them.
(RGPV JUNE 2020)
Q.8) Along with coection diagram, explain loss of charge method of measuring high resistance.
(RGPV JUNE 2020)
Q.9) Explain Hysteresis Effect. Also explain D. Arsenal Galvanometer.
(RGPV DEC 2020, NOV 2018)
Q.10) Describe the general requirements for a material to be used for shunts for ammeter and multiplier for voltmeter.
(RGPV DEC 2020)
Q.11) What do you understand by frequency meter also discuss about their types.
(RGPV NOV 2019)
Q.12) How to use Lloyd Fischer square for power loss. measurements.
(RGPV NOV 2019)
Q.13) For a Wheatstone bridge circuit, what would be the reading on ammeter if Vo = 6V, Ra = 12 and Ry were then to deviate by small amount to Rx = 3.0152, what would be the reading on the ammeter ?
(RGPV NOV 2019)
Q.14) Draw the B-H curve and explain it.
(RGPV NOV 2019)
Q.15) Explain the differences between the Wheatstone bridge and Kelvin’s double bridge.
(RGPV NOV 2018)
Q.16) Explain the step by step method for determination of BH curve.
(RGPV NOV 2018)
Q.17) What are the advantages of moving iron power factor meter? What are the different types of frequency meter?
(RGPV NOV 2018)
Q.18) Describe the construction detail and working of single phase induction type energy meter.
(RGPV NOV 2018)
Q.19) During the measurement of low resistance using = potentiometer the following readings were obtained) voltage drop across the low resistance under test=0.441V) voltage drop across the 0.1 ohm standard resistance = 1.0235V, Calculate the value of unknown resistance, current and power lost in it.
(RGPV NOV 2018)
— Best of Luck for Exam —
