Can I use 3 phase wattmeter in the single phase supply?

Can I use 3 phase wattmeter in the single phase supply?
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1 Answer

Answer :

The three-wire, three-wattmeter connection has the advantages of indicating the power in each individual phase (not possible in the two-wattmeter connection) and phase to neutral voltages. In a single-phase system there are just two
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Illustrate how can you use a single-phase wattmeter to measure 3 phase reactive power in a circuit?

Description : Illustrate how can you use a single-phase wattmeter to measure 3 phase reactive power in a circuit?

Last Answer : We can measure reactive power of 3 phase circuit by dingle phase wattmeter by connecting the current coil in series with a line or load and connecting the pressure coil across the other two lines.  Reactive power = 3√ V * I * sinϕ Watts. 

A single phase wattmeter rated for 500 V; 5A is having full scale deflection of 1000 watt. What is multiplying factor of the wattmeter?

Description : A single phase wattmeter rated for 500 V; 5A is having full scale deflection of 1000 watt. What is multiplying factor of the wattmeter?

Last Answer : Answer :

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

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. 

The potential coil of a single phase dynamometer wattmeter has 4840 Ohm resistance. Voltage across the load is

Description : The potential coil of a single phase dynamometer wattmeter has 4840 Ohm resistance. Voltage across the load is 220 V. With the potential coil connected on the load side, the meter indicates 100 W. Approximate percentage error due to wattmeter connection is (A) 11% (B) 9% (C) 1.1% (D) 3%

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The pressure coil of a wattmeter should be connected on the supply side of the current coil when?

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

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A ground on a particular phase of a three-phase low voltage distribution system would be indicated by a _____________. A. high switchboard wattmeter reading B. low switchboard wattmeter reading C. dark or dim switchboard ground detecting light D. bright switchboard ground detecting light

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

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In the measurement of power of balanced load by two wattmeter method in a 3-phase circuit, The readings

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While measuring power in a three phase load by two wattmeter method, the reading of two wattmeter are

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 

For power measurement of three phase circuit by two wattmeter method, when the value of power factor

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

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The minimum number of wattmeter(s) required to measure 3-phase, 3-wire balanced or unbalanced power is

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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 

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Two wattmeter method is employed to measure power in a 3 -phase balanced system with the current coil ...

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The current coil of a wattmeter is connected to the CT of R-phase....

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

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In a 3-phase power measurement by two wattmeter method the reading of one of the wattmeter was zero...

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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.

In a 3-phase power measurement by two wattmeter method, both the wattmeters had identical readings...

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What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?

Description : What is the supply rated o/p if two single phase transformer connect to give three phase o/p from a three phase I/p?

Last Answer : A. Each transformer is only capable of supplying 86.6%of its o/p rating

The voltage of the single phase supply to residential consumers is (a) 110 V (b) 210 V (c) 230 V (d) 400 V

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A single phase transformer is designed to operate from 50 Hz, 1100 V supply and to have an output voltage

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If a 220/440 V, 50 Hz, 5 KVA, single-phase transformer operates on 220V, 40Hz supply with secondary winding...

Description : If a 220/440 V, 50 Hz, 5 KVA, single-phase transformer operates on 220V, 40Hz supply with secondary winding open circuited: (A) both the eddy current and the hysteresis losses will decrease ... losses will increase (D) eddy current losses will increase but the hysteresis losses will remain the same

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A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by...

Description : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will?

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To conduct an in-circuit test of a transistor, you should use a/an ____________. A. voltmeter or transistor tester B. impedance meter C. ohmmeter or transistor tester D. wattmeter

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Use Voltmeter, ammeter, wattmeter to determine active, reactive and apparent power consumed in given R—C series circuit, draw phasor diagram.

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Use Voltmeter, ammeter, wattmeter to determine active, reactive and apparent power consumed in given R-L series circuit, draw phasor diagram.

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Description : What is the reason why wattmeter indicates only copper loss during transformer short circuit test ?

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Description : When was the wattmeter invented?

Last Answer : Feel Free to Answer

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Description : A current-carrying conductor making electrical contact with a wiring conduit will be indicated by a _____________. A. high switchboard wattmeter reading B. totally dark switchboard ground detecting light C. low switchboard wattmeter reading D. all of the above

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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

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A wattmeter is used to determine ____________. A. the power being consumed by electrical equipment B. partial circuit resistance C. current flowing in a circuit D. voltage existing between two points in a circuit

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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 load B. angle of coil displacement C. inertia of the movable coil D. high resistance from the load

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The basic meter movement responds to the flow of current through its coil. Therefore, this meter movement may be used as a/an _____________. A. voltmeter by placing a resistance in parallel with the coil B. ohmmeter by placing another meter movement in parallel with the coil C. wattmeter by placing a battery in parallel with the coil D. ammeter by placing a low resistance in parallel with the coil

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A suspected 'open' in a motor field can be tested by using a/an ____________. A. potentiometer B. megger C. wattmeter D. ammeter

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ECE Board Exam November 1996 What is the applied power if a thermal RF wattmeter is connected to a transmitter through a variable attenuator? The wattmeter reads 84 mW when 15 dB of attenuation is used. A. 4.656 watts B. 2.656 watts C. 3.656 watts D. 2.856 watts

Description : ECE Board Exam November 1996 What is the applied power if a thermal RF wattmeter is connected to a transmitter through a variable attenuator? The wattmeter reads 84 mW when 15 dB of attenuation is used. A. 4.656 watts B. 2.656 watts C. 3.656 watts D. 2.856 watts

Last Answer : B. 2.656 watts