15 views
in Electrical Measurements and Instrumentation by
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-wire balanced load 

4. Balanced source with 3-phase 4-wire unbalanced load 

5. unbalanced and unbalanced source 

 

(a) 1 only (b) 2, 3 and 5 (c) 1, 2, 3, 4 and 5 (d) 1, 2, 3 and 5 

Your answer

Thanks for your contribution. Feel free to answer this question. Please avoid short answer. Your answer is most welcome. Be genuine.

Upload image or document:

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
Are you a robot ? (Y = Yes / N = No)
To avoid this verification in future, please log in or register.

1 Answer

0 votes
by

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-wire balanced load 

4. Balanced source with 3-phase 4-wire unbalanced load 

5. unbalanced and unbalanced source 

 

(a) 1 only (b) 2, 3 and 5 (c) 1, 2, 3, 4 and 5 (d) 1, 2, 3 and 5 

Related questions

1 answer 18 views

 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 power factor and reactive power of the load is A) 0.2 & 6 kVAR B) 0.2 & 6 √3 kVAR C) 0.32 & 2 kVAR D) 0.32 & 2 √3 kVAR

asked Jun 17, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 22 views

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?

asked Mar 21, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 133 views

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

asked Mar 21, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 11 views

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

asked May 22, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 73 views

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

asked Sep 6, 2018 by Shimroz123
1 answer 14 views

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

asked May 12, 2018 in Electrical Measurements and Instrumentation by Shimroz123
0 answers 21 views

In the measurement of three phase power by two wattmeter method, if the two wattmeter readings are equal then power factor of the circuit is  (A) 0.8 lag (B) Unity (C) 0.8 lead (D) Zero 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 17 views

The power delivered to a 3-phase load can be measured by the use of two wattmeters only when the  (a) load is unbalanced (b) load is balanced (c) three phase load is connected to the source through three wires (d) three phase load is connected to the source through four wires

asked May 13, 2018 in Electrical Measurements and Instrumentation by Shimroz123
0 answers 18 views

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 

asked May 26, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 17 views

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

asked Apr 23, 2018 in Electrical Engineering by Shimroz123
0 answers 9 views

Two wattmeter method can be used in a three phase system excited with balanced three phase supply  A) To measure real power and power factor in a balanced load B) To measure reactive power in a balanced load C) To measure real power in an unbalanced load D) All of the above 

asked Apr 9, 2018 in Electrical Engineering by Zeeshan
1 answer 23 views

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

asked Apr 28, 2018 in Network Analysis by Shimroz123
0 answers 22 views

Measurement of power by voltmeter and ammeter method in a circuit resulted in calculated maximum errors of ±1 % and ± 2 %, respectively. The likely error in calculated power is (A) ± 3 % (B) ± 0.022 % (C) ± 1.5 % (D) ± 0.22 % 

asked Jun 4, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 16 views

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

asked Apr 12, 2018 in Electrical Engineering by Shimroz123
1 answer 27 views

Two wattmeters are used to measure the power in a 3 -phase balanced system. What is the power factor of the load when one wattmeter reads twice the other ?  (a) 0 (b) 0.5 (c) 0.866 (d) 1

asked Apr 23, 2018 in Electrical Engineering by Zeeshan
1 answer 16 views

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

asked Apr 14, 2018 in Electrical Engineering by Shimroz123
0 answers 70 views

The power in a 3-phase load is measured by two watt meters. If one watt meter reads zero, then the load power factor is (A) Zero (B) 0.5 (C ) 0.866 (D) unity 

asked Jun 4, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 11 views

The measurement range of an ammeter can be increased by using a:

asked May 22, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 12 views

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

asked May 20, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 11 views

 In a household single phase induction type wattmeter, the meter can be reversed by: - a) reversing the supply terminals b) reversing the load terminal c) opening the meter connection and reversing either the potential coil terminals or current coil terminals d) opening the meter and reversing the connection of both the potential coil terminals and current coil terminals

asked Apr 14, 2018 in Instrumentation and control by Shimroz123
1 answer 11 views

List any two methods of reactive power measurement in 3 phase circuit.

asked Sep 6, 2018 by Shimroz123
0 answers 14 views

If a dynamometer wattmeter is connected in an ac circuit, the power indicated by the wattmeter will be (a) volt-ampere product (b) average power (c) peak power (d) instantaneous power 

asked May 26, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 12 views

Power (P) in a 3 phase circuit with two watt meters at unity power factor is (W1 & W2 = watt meter readings)

asked May 15, 2018 in Electrical Engineering by Shimroz123
0 answers 70 views

. If the peak transmitted power in a radar system is increased by a factor of 16, the maximum range will be increased by a factor of : (A) 2 (B) 4 (C) 8 (D) 16

asked Apr 14, 2018 in Electrical Engineering by Shimroz123
1 answer 9 views

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 of the impedance of the voltage coil circuit  A) (i) is true but (ii) is false B) (i) is false but (ii) is true C) Both (i) and (ii) are true D) Both (i) and (ii) are false

asked May 20, 2018 in Electrical Measurements and Instrumentation by Shimroz123
0 answers 12 views

The voltage profile of a n-bus power system can be improved by controlling the (A) load angles (B) active power flows (C) reactive power flows (D) complex power flows 

asked Jun 4, 2018 in Power system by Shimroz123
1 answer 24 views

In a balanced 3 -phase 200 V circuit, the line current is 115.5 A. When the power is measured by two wattmeter method, one of the wattmeters reads 20 kW and the other one reads zero. What is the power factor of the load ?

asked Apr 23, 2018 in Electrical Engineering by Zeeshan
0 answers 45 views

For a balanced three phase star connected load for which line voltage is 230V and per phase resistance and reactance is 6 Ohm and 8 Ohm respectively. Calculate: 1) phase voltage 2) line current 3) power factor 4) total power absorbed

asked Aug 12, 2018 in Basic electrical and electronics engineering by Quiz
1 answer 27 views

Which method can be used for absolute measurement of resistance? A. Ohm's law method B. Wheatstone bridge method C. Both A & B D. None of these. 

asked Apr 12, 2018 in Electrical Engineering by Shimroz123
1 answer 11 views

The resolving power of a spectrometer consisting of collimator, a grating and a telescope can be increased by (A) increasing the angular magnification of the telescope (B) increasing the period of the grating (C) decreasing the period of the grating (D) decreasing the slit-width of the collimator

asked Apr 26, 2018 in Electronics Engineering by Shimroz123
1 answer 17 views

The steady state stability of the power system can be improved by (A) using machines of high impedance (B) connecting transmission lines in series. (C) connecting lines in parallel. (D) reducing, the excitation of the machines.

asked May 12, 2018 in Power system by Shimroz123
0 answers 13 views

In 3-phase induction motors, speeds higher than synchronous speed can be had by  (1) line voltage control (2) rotor slip power control (3) rotor resistance control [4) frequency control

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
1 answer 4 views

State two advantages and two disadvantages of photoelectric pick-up speed measurement method.

asked Sep 9, 2018 by Shimroz123
1 answer 22 views

Name two methods for measurement of low, medium and high resistance. Give one advantage and one limitation of V- I method.

asked Sep 6, 2018 by Shimroz123
1 answer 14 views

A 3-phase 11 kV generator feeds power to a constant power unity power factor load of 100 MW through a 3-phase transmission line. The line-to line voltage at the terminals of the machine is maintained constant at 11 kV. The per unit positive sequence impedance of the line based on 100 MVA and 11 kV is j0.2. The line to line voltage at the ... load to increase the line-to-line voltage at the load terminals to 11 kV is  (A) 100 MVAR (B) 10.1 MVAR (C) -100 MVAR (D) -10.1 MVAR

asked May 25, 2018 in Power system by Shimroz123
1 answer 137 views

A 3-phase, 11 kv, 50 Hz, 200 kW load has a power factor of 0.8 lag. A delta connected 3-phase capacitor is used to improve the power factor to unity. The capacitance perphase of the capacitor in micro-farads is?

asked Mar 27, 2018 in Power system by Shimroz123
2 answers 68 views

Explain how technical losses can be reduced by use of energy efficient transformer in Transmission and Distribution system.

asked Oct 3, 2018 in Energy Conservation And Audit by Shimroz123
1 answer 23 views

Two 3-phase, Y-connected alternators are to be paralleled to a set of common busbars. The armature has a per phase synchronous reactance of 1.7 Ohm and negligible armature resistance. The line voltage of the first machine is adjusted to 3300 V and that of the second machine is adjusted to 3200 V. The machine voltages are in phase at the ... are paralleled. Under this condition, the synchronizing current per phase will be  (A) 16.98 A (B) 29.41 A (C) 33.96 A (D) 58.82 A

asked May 17, 2018 in Alternator by Shimroz123

Welcome to electronics2electrical.com here you can ask questions related to electrical, electronics, mechanical, telecommunication, instrumentation, computer, mathematics, physics etc.
Be respectful to all the members. Do not copy and paste the answers from other websites which have copyright content. While asking question give full details about it.

Categories

Most popular tags

power motor dc circuit transformer voltage current used system phase resistance factor synchronous load ac energy induction electric generator series frequency between speed capacitor use electrical meter line difference control type mosfet transmission magnetic plant high single instrument bjt unit source advantages function diode and machine winding field define torque parallel amplifier supply shunt thyristor motors electricity arduino maximum time relay armature problem value on transformers types coil diagram state flow ratio material three formula starting direction theorem method emf operating efficiency digital wave microprocessor test instruments inductance loss measure operation connected signal low applications effect single-phase network temperature working constant losses different law wattmeter measuring compare controlled breaker drive device logic rc full switch flux wire resistivity disadvantages free of materials machines angle force converter conductor transistor gain open protection scr core measurement number bridge principle generators reactance circuits negative the friction iron loop short pole battery conservation steam resistors hysteresis computer using analog lines secondary station gate a rectifier inverter linear induced relays nuclear capacitance basic characteristics design direct work rotor electronics ammeter forces diesel damping rlc connection factors capacitors minimum insulation moving regulation running self systems air fault range main stability quality starter igbt eddy alternator ideal rl average 3-phase plants arc thermal error fuzzy biasing dielectric pressure balanced superposition errors copper rotation feedback impedance measured electronic electrons charge inductive transfer explain start off back curve over solar is three-phase tariff locomotive peak bias zener engineering commutator surge conductors rating universal potentiometer density permanent mechanical transducer capacity memory adc excitation two fuse pure harmonics application semiconductor inductor internal pmmc reaction welding resonance traction permeability breakers rms designed electromagnetic si generation brushes switching capacitive shaded rate 1 distribution resistor methods delta star oscillator reluctance simplification algebra 8085 boolean weston dynamometer insulating strength installation definition fuel heating earth units

8,450 questions

7,047 answers

133 comments

3,086 users

...