Why does the core of a transformer need to be laminated?

1 Answer

Answer :

Transformer cores are laminated to reduce eddy current loss.

Related questions

Last Answer : Transformer core is laminated to reduce Eddy current losses.

Description : The main purpose of using core in a transformer is to (A) decrease iron losses (B) eliminate magnetic hysteresis (C) reduce reluctance of the common magnetic circuit (D) prevent eddy current loss

Last Answer : Reduce Relucatnce of the common magnetic circuit.

Description : State any four characteristics of core type transformer.

Last Answer : Characteristics of core type transformer: i) It has one window. ii) It has one magnetic circuit. iii) Core surrounds the winding. iv) Average length of core is more. v) Area of cross ... Better cooling for winding. vii) Mechnical strength is comparatively less. viii) Repair and maintenance is easy.

Description : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is

Last Answer : A 40 kVA transformer has a core loss of 400 W and a full load copper loss of 800 W. The proportion of full load at maximum efficiency is 0.707

Description : The core construction is like spokes of a wheel in following transformer:  (A) Berry Type Transformer (B) Core Type Transformer (C) Shell Type Transformer (D) None of the above

Last Answer : The core construction is like spokes of a wheel in following transformer:  Berry Type Transformer

Description : The desirable properties of transformer core material are  (1) low permeability and low hysteresis loss. (2) high permeability and high hysteresis loss. (3) high permeability and low hysteresis loss. (4) low permeability and hysteresis loss.

Last Answer : The desirable properties of transformer core material are high permeability and low hysteresis loss.

Last Answer : Material used for construction of transformer core is usually silicon steel.

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.

Description : The size of a transformer core will depend on?

Last Answer : The size of a transformer core will depend on frequency and area of the core.

Description : Reduction in core losses and increase in permeability are obtained with transformer employing?

Last Answer : Reduction in core losses and increase in permeability are obtained with transformer employing core built-up of laminations of cold rolled grain oriented steel.

Description : Why poles of dc machine are laminated?

Last Answer : Poles of DC machines are laminated to reduce the eddy current losses in the poles.

Description : Laminated cores, in electrical machines, are used to reduce?

Last Answer : Laminated cores, in electrical machines, are used to reduce eddy current loss.

Description : In AC. circuits, laminated iron is invariably used in order to?

Last Answer : In AC. circuits, laminated iron is invariably used in order to reduce eddy current loss.

Description : How to Clean Laminated Floors ?

Last Answer : How to Clean Laminated Floors Laminated floors offer beauty and style just like hardwood or stone floors, but with much easier maintenance. Made with dense fibers and wood particles, the flooring material is ... indoors. Clean up spills as soon as possible for easier removal, and you're all set.

Description : Why is the armature of DC generator laminated?

Last Answer : The armature of DC generator is laminated to reduce eddy current losses.

Description : 8 The transformer core is laminated to A. Reduce the copper losses B. Reduce the core losses C. Reduce the eddy current losses D. None of the above

Last Answer : C. Reduce the eddy current losses

Description : State the material used for making (1) Magnetic Core (2) Fuse element  

Last Answer : The material used for making of:  (1) Magnetic Core : Iron, cobalt, Nickel, CRGO, HRGO , silicon steel  (2) Fuse Element: Tin- lead wire, Tinned copper wire 

Description : Core type transformers are popular in___________.  (A) High voltage applications (B) Low voltage applications (C) All of the above (D) None of the above

Last Answer : Core type transformers are popular in High voltage applications

Description : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is (A) 28.2 mm (B) 26.4 mm (C) 24.4 mm (D) 22.0 mm

Last Answer : A single core cable is designed to work for a single phase system with a peak voltage of 220 kV. The maximum permissible stress in the dielectric is not to exceed 20 kV/mm. For economical size, the overall core diameter of the cable is 22.0 mm

Description : A ferrite core has less eddy current loss than an iron core because?

Last Answer : A ferrite core has less eddy current loss than an iron core because ferrites have high hysteresis.

Description : State the need of biasing of BJT.

Last Answer : Need of biasing: The basic need of transistor biasing is to keep the base-emitter (B-E) junction properly forward biased and the collector-emitter (C-E) junction properly reverse biased ... transistor biasing is necessary for normal and proper operation of transistor to be used for amplification. 

Description : What is regulator ? State its need.

Last Answer : A voltage regulator is a circuit or device designed to deliver a constant voltage at its output regardless of changes in ac supply voltage and load current. Need:- A voltage regulator is one ... unexpected result or damage one of the components in the circuit, hence voltage regulator is needed.

Description : State the need of cascade amplifier.

Last Answer : Most systems a single transistor amplifier does not provide sufficient gain or bandwidth or will not have the correct input or output impedance matching. Hence cascade amplifier is use which consist more than one stages of amplification.

Description : What is need of regulated power supply?

Last Answer : A regulated power supply is used to ensure that the output remains constant even if the input changes. But sometimes main supply voltage, load, and surrounding temperature keep changing and altering the ... power supply is needed that will accept an AC input and give a constant DC output.

Description : A single core lead sheathed cable with two dielectrics of permittivity 4 and 3, respectively, are subjected to same maximum stress. If the conductor diameter is 1.5 cm, the outer diameter of the first dielectric is (A) 1.125 cm (B) 1.5 cm (C ) 2 cm (D) 8 cm

Last Answer : A single core lead sheathed cable with two dielectrics of permittivity 4 and 3, respectively, are subjected to same maximum stress. If the conductor diameter is 1.5 cm, the outer diameter of the first dielectric is 2 cm 

Last Answer : The armature core of a D.C. generator is usually made of silicon steel.

Last Answer : When a conductor carries more current on the surface as compared to core, it is due to skin effect.

Description : In DC generators lamination core are generally made of?

Last Answer : In DC generators lamination core are generally made of silicon steel.

Description : Describe the need of level measurements.

Last Answer : In almost all industries, vast quantities of liquid such as water ,solvents, chemicals etc. are used in number of processes. It is widely employed to monitor as well as measure ... and therefore its measurement becomes important in a variety of processes encountered in modern manufacturing plants.

Description : State the need of automation. 

Last Answer : Need of Automation in Process : * To fulfill the demand of product at right time. * To reduce the human errors and involvement of human being in the process. * For better productivity. * For better ... of process. * For better quality. * For reducing man power. * For reducing cost of product.

Description : Explain the need of energy conservation in present scenario.

Last Answer : Need of energy conservation in present scenario: 1. Fossil fuels like coal, oil which have taken no. of years to form and now they are on the verge of depleting soon. 2. In last ... protection and integrated economic and social development. 9. Energy saved is as good as energy generated. 

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 : What type of processor does the alienware m15x have?

Last Answer : http://www.laptopmag.com/review/laptops/alienware-m15x.aspx?mode=specs

Description : The area of the yoke in a transformer is taken 15 to 20% larger than that of the core. Why?

Last Answer : By keeping yoke area 15-20% higher ,the flux density in the yoke is reduced, resulting into reduction in iron losses for yoke. The reduced core area results working flux density and needed to increase the number of turns.

Description : What is the purpose of laminating the core in a transformer?

Last Answer : In order to minimize eddy current loss.

Description : Where is core type and shell type construction suitable for a transformer?

Last Answer : Core type transformers are popular in High voltage applications like Distribution transformers, Power transformers, and obviously auto transformers. Where as, Shell type transformers are ... voltage applications like transformers used in electronic circuits and power electronic converters etc

Description : What are the advantages of shell type transformer over core type transformers?

Last Answer : In shell type transformers the coils are well supported on the all sides and so they can withstand higher mechanical stresses developed during short circuit conditions. Also the leakage reactance will be less in shell type transformers.

Description : 72 Harmonics in transformer result in A. Increased core losses B. Increased I2R losses C. Magnetic interference with communication circuits D. All of the above

Last Answer : D. All of the above

Description : [53] The iron loss of the transformer is negligible during short circuit test because A. The entire input is just sufficient to meet Cu losses only B. Flux produced is a small fraction of the normal flux C. Iron core becomes fully saturated D. Supply frequency is held constant

Last Answer : B. Flux produced is a small fraction of the normal flux

Description : 49 The open circuit test is carried out in a transformer to find the A. Cu loss B. Core loss C. Total loss D. Insulation resistance

Last Answer : B. Core loss

Description : 46 The core used in high frequency transformer is usually A. Copper core B. Cost iron core C. Air core D.Mid steel core

Last Answer : C. Air core

Description : 45 The function of conservator in a transformer is A. To protect against internal fault B. To reduce copper as well as core losses C. To cool the transformer oil D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

Last Answer : D. To take care of the expansion and contraction of transformer oil due to variation of temperature of surroundings

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 : 27] In a transformer, the leakage flux of each winding is proportional to the current in that winding because A. Ohm's law applies to magnetic circuits B. Leakage paths do no saturate C. the two windings are electrically isolated D. mutual flux is confined to the core

Last Answer : B. Leakage path do not saturate

Description : 19 Transformer cores are built up from laminations rather than from solid metal so that A. Oil penetrates the core more easily B. Eddy current loss is reduced C. Less lamination is required for the windings D. Turn ratio is higher than voltage ratio

Last Answer : B. Eddy current loss is reduced

Description : 13) In an ideal transformer A. windings have no resistance B. core has no losses C. core has infinite permeability D. all of the above

Last Answer : D. All of the above

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

Description : 10] The main reason for generation of harmonics in a transformer could be A. Fluctuating load B. Poor insulation C. Mechanical vibrations D. Saturation of core

Last Answer : D) saturation of core

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 : Material used for construction of transformer core is usually A. 0.4mm to 0.5 mm B. 4mm to 5 mm C. 14mm to 15 mm D. 25mm to 40 mm

Last Answer : d) 25mm to 40mm