1 Answer

Answer :

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

Related questions

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 :  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 : 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 : 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 : 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 : 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

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 : 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 : 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 : 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 : 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 : 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.

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.

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.

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.

Description : State the principle of wattmeter. 

Last Answer : Working Principle of Wattmeter: It consists of two stationary coils, called current coils and one moving coil, called voltage or potential coil. The current coils are connected such that they ... experiences a force and tends to move in the direction as per Fleming's left hand rule. 

Description : Control systems are generally designed with damping  a) less than one  b) greater than one c) equal to one d) with any value depending upon system requirement

Last Answer : Control systems are generally designed with damping  less than one 

Description : A d.c. potentiometer is designed to measure up to about 2V with a slide wire of 800 mm. A standard cell of emf 1.18V obtains balance at 600 mm. A test cell is seen to obtain balance at 680 mm. The emf0fthe test cell is  A)1.00V B)1.34V C)1.50V D)1.70V 

Last Answer : A d.c. potentiometer is designed to measure up to about 2V with a slide wire of 800 mm. A standard cell of emf 1.18V obtains balance at 600 mm. A test cell is seen to obtain balance at 680 mm. The emf0fthe test cell is 1.34V

Description : Integrating principle in the digital measurement is the conversion of   (a) Voltage to time (b) Voltage to frequency (c) Voltage to current (d) Current to voltage

Last Answer : Integrating principle in the digital measurement is the conversion of Voltage to frequency

Last Answer : Electrostatic instrument uses the principle of the variation of Capacitance with the voltage.

Last Answer : The principle of operation of Q-meter is based on Series resonance.

Last Answer : The principle on which vector voltmeter is based is that it measures the amplitude of a single at two points and at the same time measures their phase difference

Description : Eddy current damping cannot be used for moving iron instrument because

Last Answer : Eddy current damping cannot be used for moving iron instrument because the presence of a permanent magnet required for such purpose would affect the deflection and hence the reading of the instrument

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

Last Answer : Answer : The voltage applied in this test is limited to 5% to 10% of the rated voltage . As a result, much less mutual flux ( Φm) is produced in the core than normal mutual flux. Since ... Φm² , the core loss is practically zero. Thus the whole of the wattmeter reading is considered copper loss.

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

Last 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

Description : When was the wattmeter invented?

Last Answer : Feel Free to Answer

Description : An open occurring within the field rheostat of an AC generator can be detected by short circuiting its terminals and observing a ____________. A. negative deflection of the wattmeter pointer B. ... of the wattmeter pointer C. buildup of alternator voltage D. low, but constant alternator voltage

Last Answer : Answer: C

Description : 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

Last Answer : Answer: C

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

Last Answer : Answer: B

Description : A current-carrying conductor makes accidental contact with a wiring conduit. This will be indicated by a _____________. A. low switchboard wattmeter reading B. high switchboard wattmeter reading C. darkened switchboard ground detecting lamp D. darkened switchboard synchronizing lamps

Last Answer : Answer: C

Description : A current carrying conductor making an electrical contact with a wiring metal conduit is indicated by a _____________. A. low switchboard wattmeter reading B. reading of 1.0 on the power factor meter C. high switchboard voltmeter reading D. totally darkened switchboard ground-detecting light

Last Answer : Answer: D

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 : 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

Last Answer : Answer: A

Description : How is a wattmeter electrically connected in a circuit? A. In series B. In parallel C. In series-parallel D. Inductively

Last Answer : Answer: C

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 : 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 ... in parallel with the coil D. ammeter by placing a low resistance in parallel with the coil

Last Answer : Answer: D

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 : Which of the instruments listed should always be connected in series with a circuit? A. Ammeter B. Megohmmeter C. Wattmeter D. Voltmeter

Last Answer : Answer: A

Description : 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

Last Answer : Answer: A

Description : Which of the meters listed should only be used after a circuit has been electrically disconnected? A. Wattmeter B. Frequency meter C. Ammeter D. Ohmmeter

Last Answer : Answer: D

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

Last Answer : Answer: B

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