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In the case of power measurement by two wattmeter method in a balanced 3Φ system with a pure inductive load both the Wattmeter will indicate the same but of opposite sign.

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Description :  In the measurement of power of balanced load by two wattmeter method in a 3-phase circuit, The readings of the wattmeters are 4 kW and 2 kW respectively, the later is being taken after reversing the connections of current coil. the ... kVAR B) 0.2 & 6 √3 kVAR C) 0.32 & 2 kVAR D) 0.32 & 2 √3 kVAR

Last Answer :  In the measurement of power of balanced load by two wattmeter method in a 3-phase circuit, The readings of the wattmeters are 4 kW and 2 kW respectively, the later is being taken after reversing the ... of current coil. the power factor and reactive power of the load is 0.2 & 6 √3 kVAR

Description : Measurement of power and power factor of a 3-phase system by two wattmeter method can be obtained in case of  1. Balanced load and balanced source  2. Balanced source with 3-phase 3-wire unbalanced load  3. Unbalanced source with 3-phase 3 ... b) 2, 3 and 5 (c) 1, 2, 3, 4 and 5 (d) 1, 2, 3 and 5 

Last Answer : Measurement of power and power factor of a 3-phase system by two wattmeter method can be obtained in case of  1. Balanced load and balanced source  2. Balanced source with 3-phase 3-wire unbalanced load  3. Unbalanced source with 3- ... b) 2, 3 and 5 (c) 1, 2, 3, 4 and 5 (d) 1, 2, 3 and 5 

Description : For power measurement of three phase circuit by two wattmeter method, when the value of power factor is less than 0.5 lagging:

Last Answer : For power measurement of three phase circuit by two wattmeter method, when the value of power factor is less than 0.5 lagging: One of the wattmeter connections will have to be reversed

Description : In the measurement of power by two wattmeter method, when the readings of the two wattmeters are equal, the power factor is (A) Zero (B) Leading (C) Lagging (D) Unity

Last Answer : In the measurement of power by two wattmeter method, when the readings of the two wattmeters are equal, the power factor is Unity

Description : In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The power factor of the load must be?

Last Answer : In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero. The power factor of the load must be 0.5.

Description : In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was?

Last Answer : In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was unity.

Description : The power consumed by a balanced 3-ph load is measured by two-wattmeter method. The meter readings are 8 kW and 4 kW. The power factor of the load is (A) zero (B) 0.5 (C) between zero and 0.5 (D) between 0.5 and unity

Last Answer : The power consumed by a balanced 3-ph load is measured by two-wattmeter method. The meter readings are 8 kW and 4 kW. The power factor of the load is between 0.5 and unity

Description : The minimum number of wattmeter(s) required to measure 3-phase, 3-wire balanced or unbalanced power is  A) 1 B) 2 C) 3 D) 4

Last Answer : B

Description : While measuring power in a three phase load by two wattmeter method, the reading of two wattmeter are equal and opposite, when (a) load is balanced (b) power factor is unity (c) phase angle is between 60° to 90° (d) the load is purely inductive 

Last Answer :  Option (d)  Load is purely inductive 

Description : Two wattmeter method is employed to measure power in a 3 -phase balanced system with the current coil connected in the A and C lines. The phase sequence is ABC. If the wattmeter with its current coil in A -phase line reads zero, then the power factor of the 3 -phase load will be

Last Answer : Two wattmeter method is employed to measure power in a 3 -phase balanced system with the current coil connected in the A and C lines. The phase sequence is ABC. If the wattmeter with its current coil in A -phase line reads zero, then the power factor of the 3 -phase load will be 0.5 lagging.

Last Answer : The power measurement in a balanced 3-phase circuit can be done by: One wattmeter method, Two wattmeter method, Three wattmeter method.

Description : Draw the circuit diagram for:- i) Measurement of active power in 3-phase load circuit using two wattmeter. ii) Measurement of reactive power in 3-phase load circuit using one wattmeter.

Last Answer : (i) Measurement of active power in 3- phase load circuit using two- wattmeter: (ii) Measurement of reactive power in 3- phase load circuit using one wattmeter

Description : Explain the effect of power factor on wattmeter reading in two wattmeter method for power measurement.

Last Answer : Effect of P.F. on Reading of Wattmeter in Two Wattmeter Method:

Description : State any two disadvantages of one wattmeter method of measurement of 3 phase power.

Last Answer : State any two disadvantages of one wattmeter method of measurement of 3 phase power. Disadvantages of one wattmeter method:- 1. Only used for balanced load 2. It can not be used for ... connection then neutral point must be available 4. Delta connection must be opened to connect current coil.

Description : In two -wattmeter method of power measurement, if one wattmeter shows negative reading, then the power factor of the circuit is treated as (A) Unity (B) Lagging (C) Leading (D) Zero

Last Answer : Lagging   power   factor.

Description : What is the power factor in pure resistive , capacitive , inductive load ?

Last Answer : Answer : Power factor cosΦ = 1 in pure resistive load, cosΦ = 0 in capacitive load , cosΦ = 0 in inductive load .

Description : A portable hand-held and is very handy for determining the power consumption and power factor of individual motors and other inductive devices. a) Voltmeter and wattmeter. b) Wattmeter and power factor meter. c) Light meter and flash meter.

Last Answer : Voltmeter and wattmeter.

Description : A single-phase voltage source square -wave inverter feeds pure inductive load. The waveform of the load current will be

Last Answer : A single-phase voltage source square -wave inverter feeds pure inductive load. The waveform of the load current will be triangular

Description : Consider the following statements  1) The compensating coil of a low power factor wattmeter compensates the effect of the impedance of the current coil ii) The compensating coil of a low power factor wattmeter compensates the effect ... C) Both (i) and (ii) are true D) Both (i) and (ii) are false

Last Answer : A

Last Answer : In a low power factor wattmeter the compensating coil is connected in series with pressure coil.

Last Answer : In a low power factor wattmeter the pressure coil is connected to the load side of the current coil.

Description : Draw and explain the circuit diagram for measurement of single phase power using dynamometer type wattmeter. 

Last Answer : Circuit diagram for measurement of single phase power using dynamometer type wattmeter: Explanation: It consists of two stationary coils, called current coils and one moving coil, called voltage or ... i.e. power. The meter can be calibrated directly to indicate the power in watts. 

Description : What is the working principle of 3φ induction motor?

Last Answer : When 3φ supply is given to stator, a rotating magnetic field of constant magnitude is produced. This rotating magnetic field produces induced emf in the rotor winding as per faraday's laws and ... interaction between the rotating magnetic field of stator and the field produced by the rotor current.

Description :  In dynamometer type of wattmeter, which of the coil is split up into two parts?

Last Answer :  In dynamometer type of wattmeter, which of the coil is split up into two parts?  current coil

Description : The pressure coil of a dynamometer type wattmeter is  A) Highly inductive B) Highly resistive C) Purely resistive D) Purely inductive

Last Answer : highly resistive

Description : A wattmeter is connected as shown in the figure. The wattmeter reads 

Last Answer : A wattmeter is connected as shown in the figure. The wattmeter reads Power consumed by Z2

Description : Poynting vector wattmeter is based on   (A) Seebeck effect (B) Ferranti effect (C) Induction effect (D) Hall effect

Last Answer : Poynting vector wattmeter is based on Induction effect 

Description : The torque produced in wattmeter is proportional to

Last Answer : A

Description : The current coil of a wattmeter is connected to the CT of R-phase. The potential coil is connected across Y and B phases. The wattmeter measures

Last Answer : The current coil of a wattmeter is connected to the CT of R-phase. The potential coil is connected across Y and B phases. The wattmeter measures Reactive power of R phase.

Last Answer : Wattmeter cannot be designed on the principle of moving iron instrument.

Last Answer : The pressure coil of a wattmeter should be connected on the supply side of the current coil when load impedance is high.

Last Answer : An induction wattmeter can be used for A.C. 

Last Answer : A dynamometer wattmeter can be used for both D.C. and A.C.

Last Answer : The resistance in the circuit of the moving coil of a dynamometer wattmeter should be high.

Last Answer : The average power in a pure inductive circuit is 0.

Description : Pure inductive circuit takes power from the A.C. line when?

Last Answer : It takes power when voltage decreases and current increases.

Description : The instrument for measurement of flow/ velocity is________. A. Bimetallic. C) Turbine meter. B. Manometer. D) Wattmeter

Last Answer : Turbine meter

Last Answer : Commonly used instruments in power system measurement are induction.

Description : The true power indicated by a wattmeter depends on the current flow through the load, the magnitude of the potential across the load, and the _____________. A. power factor of the load B. angle of coil displacement C. inertia of the movable coil D. high resistance from the load

Last Answer : Answer: A

Description : Which of the following meters uses a shunt connected in series with the load, but parallel with the meter movement? A. voltmeter B. power factor meter C. wattmeter D. ammeter

Last Answer : Answer: D

Description : The true power indicated by the pointer movement of a wattmeter depends on the current flow through the load, the magnitude of the potential across the load, and the ____________. A. power factor of the ... B. angle of coil displacement C. inertia of the movable coil D. high resistance from the load

Last Answer : Answer: A

Description : Which of the listed meters uses a shunt connected in series with the load, but parallel with the meter movement? A. Voltmeter B. Power factor meter C. Ammeter D. Wattmeter

Last Answer : Answer: C

Description : The power delivered to a three-phase load can be measured by the use of 2 wattmeter only when the A. Load is balanced B. 3 -phase load is connected to the source through 3 wires C. Load is unbalanced D. 3 -phase load is connected to the source through 4 wires

Last Answer : The power delivered to a three-phase load can be measured by the use of 2 wattmeter only when the  Load is unbalanced

Description : What is the reactance property at the input of a shorted quarter wavelength line? A. A parallel LC circuit B. A pure inductive reactance C. A series LC circuit D. A pure capacitive reactance

Last Answer : A. A parallel LC circuit

Description : With the help of waveforms and phasor diagrams, show the phase relationship between voltage and current in pure inductive circuit.

Last Answer : Phasor Diagram:  

Last Answer : In a pure inductive circuit The current lags applied voltage by 90 degree.

Description : In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will?

Last Answer : In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will be doubled.

Description : In a pure inductive circuit?

Last Answer : Voltage lagging in inductor

Description : Pure inductive circuit?

Last Answer : Pure inductive circuit takes power from the line during some part of the cycle and then returns back to it during other part of the cycle.

Description : A single phase 60 Hz generator supplies an inductive load of 4500kW at a power factor of 0.80 lagging by means of a 20 km long overhead transmission line. The line resistance and inductance are 0.0195 ohm and 0.60 mH ... voltage regulation of the line.  (A) 12.59% (B) 16.34% (C) 32.68% (D) 41.15% 

Last Answer : Answer is C