How to minimize Hysteresis loss?

1 Answer

Answer :

By using good magnetic material.
By using less value of Magnetic flux density

Related questions

Description : Mention the factors on which hysteresis loss depends?

Last Answer : (i) Quality and amount of iron in the core (ii) Flux density and (iii) Frequency.

Description : What is hysteresis loss in transformer?

Last Answer : The magneto motive force or mmf applied in the transformer core is alternating. For every cycle due to this domain reversal, there will be extra work done. For this reason, there will be a consumption of electrical energy which is known as Hysteresis loss of transformer.

Description : How do we minimize eddy current loss?

Last Answer : A. By laminating the core we can minimize eddy current loss.

Description : How to minimize Eddy current loss?

Last Answer : By using less thickness of laminations By using less value of Magnetic flux density

Description : 70] Silicon steel used in laminations mainly reduces A. Hysteresis loss B. Eddy current losses C. Copper loss D. All of the above

Last Answer : A. Hysteresis loss

Description : 69 In case there are burrs on the edges of the laminations of the transformer, it is likely to result in A. Vibrations B. Noise C. Higher eddy currents loss D. Higher hysteresis loss

Last Answer : C. Higher eddy currents loss

Description : 43 The purpose of providing an iron core in a transformer is to A.Provide support to windings B. Reduce hysteresis loss C. decrease the reluctance of the magnetic path D. reduce eddy current losses

Last Answer : C. Decrease the reluctance of the magnetic path

Description : 9 Which loss is not common between a transformer and rotating machines? A. Eddy current loss B. Copper loss C. Windage loss D. Hysteresis loss

Last Answer : A. Eddy current loss

Description : 24 Transformer cores are laminated in order to A. simplify its construction B. minimise eddy current loss C. reduce cost D. reduce hysteresis loss

Last Answer : B. Minimise eddy current loss

Description : 17. Which type of loss is not common to transformer and rotating machines? A. Eddy current loss B. Copper loss C. Hysteresis loss D. Windage loss

Last Answer : D. Windage loss

Description : Which of the following properties is not necessarily desirable in the material for transformer core? A. Mechanical strength B. Low hysteresis loss C. High thermal conductivity D. High permeability

Last Answer : C) high thermal conductivity

Description : A transformer at 25 Hz develops 20 W hysteresis loss and 50 W eddy current loss. If the applied voltage and frequency are doubled, the new core losses are (A) 140 W (B) 180 W (C) 240 W (D) 480 W

Last Answer : A transformer at 25 Hz develops 20 W hysteresis loss and 50 W eddy current loss. If the applied voltage and frequency are doubled, the new core losses are 240 W

Description : What are the tests done to minimize internal faults?

Last Answer : 1.Dissolved Gas Analysis (DGA): Faults due to arcing, high current breakdown of oil, localized sparking, partial discharge of oil, localized overheating or hot spots, etc. causes ... Over current relays with under voltage blocking 6.Zero sequence protection. 7.Negative phase sequence protection

Description : The armature cores of the D.C. motors are constructed with laminations to ___________. A. eliminate hysteresis B. minimize brush sparking C. reduce eddy current losses D. compensate for armature reaction

Last Answer : Answer: C

Description : The armature cores of the D.C. motors are constructed with laminations to ___________. A. eliminate hysteresis B. minimize brush sparking C. reduce eddy current losses D. compensate for armature reaction

Last Answer : Answer: C

Description : 71 High frequency transformers sometimes make use of ferrite cores because it has A. High specific gravity B. High resistance C. High hysteresis D. low permeability

Last Answer : B. High resistance

Description : 42 The efficiency of a transformer will be maximum when A. copper losses = hysteresis losses B. Hysteresis losses = eddy current losses C. Eddy current losses = copper losses D. Copper losses = iron losses

Last Answer : D. Copper losses = iron losses

Description : 7 The main advantage of auto transformer over a two winding transformer is A. Hysteresis losses are reduced B. Saving in winding material C. Copper losses are negligible D. Eddy losses are totally eliminated

Last Answer : A) hysteresis losses is reduced

Description : How can eddy current loss be minimized?

Last Answer : By laminating the core.

Description : Is copper loss affected by change in power factor?

Last Answer : A. Yes. Copper loss varies inversely with power factor.It depends on current in primary and secondary windings. It is known that current required is higher when power factor is lower

Description : What is Eddy current loss in transformer?

Last Answer : In transformer, we supply alternating current in the primary, this alternating current produces alternating magnetizing flux in the core and as this flux links with secondary winding, there will be induced ... dissipated as heat. This type of energy loss is called eddy current loss of transformer.

Description : Which of the following losses is/are present in every direct current generator armature? A. Winding copper loss B. Core eddy current loss C. Magnetic hysteresis loss D. All of the above.

Last Answer : Answer: D

Description : Materials that retain a large part of their magnetization, after the magnetizing force is removed, are said to have _____________. A. low hysteresis loss B. high flux density C. high permanence D. high permeability

Last Answer : Answer: C

Description : As an armature revolves within a magnetic field, friction is developed between the rotated magnetized particles as they pass through each magnetization cycle. This results in ____________. A. copper loss B. eddy-current loss C. hysteresis loss D. armature reaction

Last Answer : Answer: C

Description : The heating of conductors as a result of resistance in a distribution circuit causes a power loss expressed as _____________. A. line droop B. line loss C. IR drop D. hysteresis

Last Answer : Answer: B

Description : The armature of a dc machine is laminated to reduce: (A) Eddy current loss (B) Hysteresis loss (C) copper losses (D) friction and windage losses

Last Answer : Ans: A Thinner the laminations, greater is the resistance offered to the induced e.m.f., smaller the current and hence lesser the I2R loss in the core.

Description : A 220/440 V, 50 Hz, 5 KVA, single phase transformer operates on 220V, 40Hz supply with secondary winding open circuited. Then (A) Both eddy current and hysteresis losses decreases. (B) Both ... same but hysteresis loss increases. (D) Eddy current loss increases but hysteresis loss remains the same.

Last Answer : (A) Both eddy current and hysteresis losses decreases.

Description : What are the transformer losses?

Last Answer : Answer: TRANSFORMER LOSSES - There are mainly two kinds of losses in a transformer namely 1. Copper loss (ohmic loss) and 2.magnetic loss (core loss). Copper losses are caused by the ... ohmic loss the following two losses are also present in the transformer stray load loss and dielectric loss.

Description : Why Silica gel is used in transformers?

Last Answer : Silica Gel is used to remove the moisture in the air entering in to the transformer. During the breathing of the transformer air enters in to the transformer. This air makes contact with the hot ... Silica gel crystals will be in blue color initially and after absorbing moisture it turns to pink.

Description : What are the conditions for parallel operation of two transformers ?

Last Answer : Transformers which are to be operated parallel should have to satisfy the following conditions: Polarities of both the transformers should be same else lead to short circuit Voltage rating of ... Phase displacement of transformers should be same Phase sequence of two transformers should be same

Description : At what power maximum efficiency of power transformer and distribution transformer is designed

Last Answer : Maximum efficiency of the transformer is attained at certain load factor (α) when core losses of transformer is equal to the copper losses. PCore loss = α ^2 X PCopper loss From the ... the day. Hence distribution transformers are designed to have maximum efficiency at 50% of the rated full load

Description : What happen when Transformer is given DC supply ?

Last Answer : When DC supply is given to the transformer primary winding no back emf is induced in the transformer. Importance of Back emf is that it limits the current drawn by the machine. In the absence ... in burning down of primary winding. So when dc supply is given to transformer primary windings will burn

Description : During No load why the power factor of the transformer is very low ?

Last Answer : Current flowing through the transformer consists of two components. Magnetizing current (Im) which is in quadrature (90 0 ) to the applied voltage and in phase current which is in phase to the applied voltage ... power factor of transformer during no load condition will by in the order of 0.1 to 0.2

Description : What is the significance of vector grouping in Power Transformers?

Last Answer : Answer:Every power transformer has a vector group listed by its manufacturer. Fundamentally it tells you the information about how the windings are connected (delta or wye) and the phace difference betweent ... Delta primary, Wye Secondry and the current is at 11 o clock reffered to the voltage.

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

Description : How to connect two single phase transformer to give three phase o/p from a three phase I/p ?

Last Answer : A. They would have to connect in an open-delta.

Description : What advantage has the star connection over the delta connection ?

Last Answer : A. Each star connection transformer is wound for only 57.7% of line voltage . In hv transmission, this admits of much smaller transformer being built for high voltage than possible with delta connection, because of less insulation.

Description : What is the advantage is obtained in the delta connection ?

Last Answer : A. When three transformer are obtained in delta, one may be removed and two remaining unit will carry 57.7% of the original three phase load and thus maintain the continuity of supply.

Description : What is the 3 ph transformer ?

Last Answer : A. A 3ph transformer is that transformer which is equivalent to three single phase transformer but wound on one core and enclosed within one common case.

Description : What parameters or technical particulars are important to be considered while designing protection scheme of the transformer?

Last Answer : 1.Network Diagram showing the position of the transformer in the system 2.kVA or MVA rating of the transformer 3.Fault Level at the transformer 4.Voltage Ratio 5.Winding Connections 6.Per Unit ... Oil Filled 11.Length and area of cross section of the connecting leads between CTs and Relay Panel

Description : What can be the reasons for the failure of the transformer?

Last Answer : Answer: Transformer is one of the most expensive equipments in the Power System. Failure of the transformer can cause outage of power supply for even days. However, multiple things can go wrong with ... relays. 3.Short Circuits 4.Open Circuits 5.Earth Faults 6.Over Voltage 7.Reduced system frequency

Description : How Transformer Protection provided for internal faults?

Last Answer : 1.Bucholz Relay (1st Stage Alarm and 2nd Stage Trip) 2.Sudden Pressure Relay (1st Stage Alarm and 2nd Stage Trip) 3.Pressure Relief Valve (1st Stage Alarm and 2nd Stage Trip) 4.Pressure Switch ... 8.Gas Temperature Indicator (Alarm) 9.Silicon Breather (Passive - no alarm) 10.Smoke Detector (Alarm)

Description : What are the reasons for Oil degradation?

Last Answer : 1.Degradation 2.Oxidation 3.Contamination a) Dielectric breakdown voltage indicates the presence of electrically conductive contaminants in oil. b) Interfacial tension and acid number (sometimes called ... c) Water content is temperature dependent. d) Power factor is also temperature dependent.

Description : How does change in frequency affect the operation of a given transformer?

Last Answer : a) Iron loss .........increases with a decrease in frequency. A 60-Hz transformer will have nearly 11% higher losses when worked on 50Hz instead of 60 Hz. However, when a 25-Hz ... ....since total loss is greater at a lower frequency, the temperature is increased with decrease in frequency.

Description : What effects are produced by change in voltage?

Last Answer : a) Iron loss.........varies approximately as V2. b) Cu loss.........it also varies as V2 but decreases with an increase in voltage if constant kVA output is assumed. c ... ..for constant kVA output, iron temperatures increase whereas Cu temperatures decrease with increase in voltages and vice-versa.

Description : Does the transformer draw any current when its secondary is open?

Last Answer : Yes, no-load primary current.

Description : In practice, what determines the thickness of the laminate or stampings?

Last Answer : Frequency.

Description : How is magnetic leakage reduced to a minimum in commercial transformers?

Last Answer : By interleaving the primary and secondary windings.

Description : What are the conditions for parallel operation of two transformers ?

Last Answer : Transformers which are to be operated parallel should have to satisfy the following conditions: Polarities of both the transformers should be same else lead to short circuit Voltage rating of ... Phase displacement of transformers should be same Phase sequence of two transformers should be same

Description : WHAT is ZIG ZAG Grounding Transformer

Last Answer : ANSWER: Three Single Phase Transformers can be connected to have a three phase Zig Zag Transformer. This system can be used for either grounding or developing a fourth WIRE from a three phase neutral. An example ... - three phase - three wire system to a 480Y/277 V - three phase - four wire system