288 views

In a transformer the resistance between its primary and secondary should be?

1 Answer

Answer :

In a transformer the resistance between its primary and secondary should be infinity.

Like 0 like

Please log in or register to answer this question.

Related questions

195 views

Description : Define: primary and secondary distribution system 

Last Answer : i) Primary Distribution:  It is a 3-phase, 3-wire transmission line connected in between receiving substation to Distribution substation. OR It is link between receiving substation & ... substation to consumer line. OR It is link between distribution transformer substation & consumer. 

1 answer
94 views

Description : Compare primary and secondary instruments.

Last Answer : Primary instruments  Secondary instruments  Gives magnitude of quantity in terms of physical constants of instrument  Gives reading directly of the quantity measured.  Need no calibration  ... .  e.g. magnetic meter, induction meter, hotwire meter and electrostatic meter 

1 answer
88 views

Last Answer : Primary winding of a transformer could either be a low voltage or high voltage winding.

1 answer
170 views

Description : When secondary of a current transformer is open-circuited its iron core will be?

Last Answer : When secondary of a current transformer is open-circuited its iron core will be hot because of heavy iron losses taking place in it due to high flux density.

1 answer
112 views

Description : The secondary of a current transformer is always short-circuited under operating conditions because it?

Last Answer : The secondary of a current transformer is always short-circuited under operating conditions because it avoids core saturation and high voltage induction.

1 answer
236 views

Description : A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts

Last Answer : A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts

1 answer
6.2k views

Description : Write difference between absolute & secondary instrument.

Last Answer : Absolute Instrument Secondary Instrument 1. These give magnitude of quantity in terms physical constants of instruments 1. These give reading directly of the quantity at the time of ... Raleigh current balance. 6. Examples - ammeter, voltmeter, amperehour meter, wattmeter etc.

1 answer
1.3k views

Description : Increasing the number of turns of wire on the secondary of a transformer will  (A) Decrease the secondary current (B) Increase the primary current (C) Have no effect on the secondary current (D) Increase the secondary current

Last Answer : Increasing the number of turns of wire on the secondary of a transformer will Decrease the secondary current 

1 answer
239 views

Description : If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then  (A) zero sequence currents are present on both sides of the transformer  (B) ... side  (D) zero sequence currents are present on the primary side but not on the secondary side

Last Answer : If an unsymmetrical line to ground fault occurs at the secondary terminals of a delta/star, ungrounded transformer, then zero sequence currents are absent on both sides of the transformer 

1 answer
97 views

Description : What is the mathematical relationship between resistance and conductance?

0 answers
75 views

Description : What is the relationship between power and resistance?

Last Answer : P = I2R Where P = power I = Current R = Resistance

2 answers
382 views

Description : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he

Last Answer : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he 0.52

1 answer
125 views

Description : What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known

Last Answer : What happens to the voltage in the secondary when the frequency of the supply in the primary is decreased? A) It increases B) It decreases C) It remains the same D) Cannot say unless the actual percentage increase in the frequency is known

1 answer
352 views

Last Answer : An ideal transformer has infinite values of primary and secondary inductances. The statement is false.

1 answer
190 views

Description : Write example of each type (i) Primary transducer (ii) Active transducer (iii) Electrical transducer (iv) Digital transducer

Last Answer : (i) Active transducer:-Thermocouple, piezoelectric, photovoltaic cell (ii) Primary transducer:- Bourdon tube, bellows, (iii) Electrical transducer.:- LVDT,RVDT, Hall effect, strain gauge, ... , optical pyrometer, radiation pyrometer (iv) Digital transducer:- Linear Encoder, digital taco generator

2 answers
122 views

Last Answer : The primary reason for low power factor is supply system is due to installation of induction motors.

1 answer
82 views

Description : What is the definition of a primary instrument?

0 answers
411 views

Description : Primary and Backup Protection

Last Answer : Primary and Backup Protection  B,D,G,I are the primary protection. A,C,H,J are the backup protection. About 90% of faults are clear by Primary Protection. So ... ordinated backup (primary is at various station  and backup is at control room with computer)

1 answer
128 views

Description : State the losses in secondary distribution system. 

Last Answer : The losses in secondary distribution system: a) Technical losses: 1. Due to poor voltage 2. Due to unbalance load 3. Due poor quality of transformer & its components 4. Due to poor quality ... of induction type of energy meter. 3. Lack of administration. 4. Energy theft 5. Unmetered supply

1 answer
79 views

Description : State the meaning of secondary instrument. Classify secondary instruments.

Last Answer : Secondary instruments: - Gives reading directly of the quantity being measured. - Calibrated with respect to absolute instruments  Classification of Secondary instruments:  1. Depending on the ... on permissible error: i) Standard meters ii) Substandard meters iii) First grade instruments.

1 answer
123 views

Description : State the meaning of absolute instrument and secondary instrument. 

Last Answer : Absolute instruments:   These instruments read the quantity under measurement indirectly i.e. in terms of deflection, degrees and meter constant. The actual value under measurement can be calculated ... of operation (b) Depending upon permissible percentage error. (c) Depending upon application.

2 answers
96 views

Description : Why CT is never operated with an open secondary ?

Last Answer : CT secondary should never be kept open because it will cause saturation of the core to a high level and very high voltage will appear across the secondary which can breakdown the insulation. One terminal of PT secondary is always grounded to avoid capacitive induction and for human safety

2 answers
654 views

Description : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

Last Answer : Which of the following connection of transformers will give highest value of secondary voltage ? (A) Delta primary delta secondary (B) Delta primary star secondary (C) Star primary star secondary (D) Star primary delta secondary

1 answer
97 views

Description : What do you mean by secondary instruments?

Last Answer : The instruments which will give the direct readings are called secondary instruments

1 answer
222 views

Description : What do you mean by exciting resistance and exciting reactance?

Last Answer : At no-load, a transformer behaves as a highly inductive load connected to the system which contains some resistance and inductance in parallel. The resistance is called exciting resistance R0 = V1/I w and reactance is called exciting reactance, X0 = V1/I mag

2 answers
23 views

Description : 57 In a transformer the resistance between its primary and secondary is A. Zero B. 1Ω C. 1000 Ω D. Infinite

Last Answer : D. Infinite

1 answer
1.0k views

Description : 50 The equivalent resistance of the primary of the transformer having K = 5, R1 = 0.1 ohm when referred to secondary becomes .....ohm A. 0.5 B. 0.02 C. 0.004 D. 2.5

Last Answer : A. 0.5

1 answer
7 views

Description : If we give 2334 A, 540V on Primary side of 1.125 MVA step up transformer, then what will be the Secondary Current, If Secondary Voltage=11 KV?

Last Answer : A. As we know the Voltage & current relation for transformer-V1/V2 = I2/I1 We Know, VI= 540 V; V2=11KV or 11000 V; I1= 2334 Amps. By putting these value on Relation540/11000= I2/2334 So,I2 = 114.5 Amps

1 answer
8 views

Description : What current flows in the transformer primary when its secondary is open?

Last Answer : A. When the secondary is open, there is no current in the secondary of the transformer. The primary takes a small current I0) from the source called no-load current which has a magnetizing ... ) producing the magnetic flux and a working component (I0 cosθ0) supplying real power for iron losses.

1 answer
5 views

Description : In a Tap changing transformer on which side is the tap connected, primary side or secondary side?

Last Answer : A. Tapings are always connected to high voltage winding side, because of low current. If we connect tapings to low voltage side, sparks will produce while tap changing operation due to high current.

1 answer
32 views

Description : 66 While conducting short-circuit test on a transformer the following side is short circuited A. High voltage side B. low voltage side C. primary side D. secondary side

Last Answer : B. Low voltage side

1 answer
57 views

Description : 59.An ideal transformer has infinite values of primary and secondary inductances. The statement is A. True B. False

Last Answer : B. False

1 answer
8 views

Description : 52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250

Last Answer : A. 1600

1 answer
28 views

Description : 38] In a transformer the energy is conveyed from primary to secondary? A. Through cooling coil B. Through air C. By the flux D. None of the above

Last Answer : C. By the flux

1 answer
204 views

Description : 29.In transformer terminology, the ratio 20:1 indicates that A. there are 20 turns on primary one turn on secondary B. secondary voltage is 1/20th of the primary C. primary current is 20 times greater than the secondary current D. for every 0 turns on primary, there is one turn on secondary

Last Answer : A. there are 20 turns on primary one turn on secondary

2 answers
370 views

Description : 28.In a two winding transformer, the emf /turn in secondary winding is always......the induced emf power turn in primary A. equal to k times B. equal to 1/k times C. equal D. greater than

Last Answer : C. equal

1 answer
465 views

Description : 6 In a two winding transformer, the primary and secondary induced emf E1 & E2 are always A. equal in magnitude B. anti phase with each other C. in phase with each other D. determined by load on transformer secondary

Last Answer : C. In phase with each other

1 answer
270 views

Description : The frequency of the secondary voltage of a transformer will be..... A. less than frequency of the primary voltage B. equal to the primary voltage C. greater than the frequency of the primary voltage D. much greater than the frequency of the primary voltage

Last Answer : B. Equal to the primary voltage

1 answer
45 views

Description : 12] Which is not the basic element of the transformer? A. core B. primary winding C. secondary winding D. mutual flux

Last Answer : D. Mutual flux

1 answer
58 views

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

1 answer
8 views

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

1 answer
148 views

Last Answer : Greater the secondary leakage flux less will be the secondary induced e.m.f.

1 answer
174 views

Description : Explain the effect of Harmonics on the Transformer.

Last Answer : Effect of Harmonics on the Transformer:  1. Core loss: Harmonic voltage increases the hysteresis and eddy current losses in the lamination. The amount of the core loss depends on ... small core vibrations.  5. Saturation problem: Sometimes additional harmonic voltage causes core saturation.

1 answer
496 views

Description : List two special feature of welding transformer.

Last Answer : Special features of welding transformer: i) It is a step down transformer that reduces the source voltage to a voltage desired according to the demands of the welding process. ii) Having large primary turns and less ... V ii) Secondary voltage - 40 to 60 V iii) Secondary current - 200 to 600 A

1 answer
64 views

Description : State two applications of isolation transformer

Last Answer : Applications of isolation transformer: i) Isolates the load equipment from supply ground: ii) Reduction of voltage spikes iii) It acts as a decoupling device. iv) Protects loads from harmonic distortion.

1 answer
505 views

Description : State why a transformer always have an efficiency of more than 90%.

Last Answer : As transformer is static device with no moving parts, the losses due to friction & windage are completely absent. Hence transformer has efficiency of more than 90%.

1 answer
406 views

Description : Equivalent circuit of transformer

Last Answer : Equivalent Circuit Diagram of Transformer Referred to Primary: V1 -Primary Input voltage I1 - Input Current I0- Exciting current/ No load current Im- Magnetizing component ... equivalent of secondary terminal voltage ZL- Load impedance ZL ′- Primary equivalent of load impedance

2 answers
264 views

Description : Single phase transformer

Last Answer : Single phase Transformer Transformer

1 answer
162 views

Description : What is the use of transformer?

Last Answer : The use of transformer  is to do lower or raise  the voltage or currents in an electrical  circuit.  That's quite so simple. 

1 answer
...