Laminations in the transformer core are provided to avoid

Laminations in the transformer core are provided to avoid (a) continuous air gap (c) to reduce exiting current (b) to reduce the weight (d) to reduce copper losses
by

1 Answer

Answer :

To reduce eddy current and hysterisis losses
by

Related questions

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

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

Brush sparking during commutation may be caused by ________. A. eddy currents in the armature core B. laminations in the generator field pieces C. induced current opposite to coil inductance D. coil inductance discharge occurring at commutation

Description : Brush sparking during commutation may be caused by ________. A. eddy currents in the armature core B. laminations in the generator field pieces C. induced current opposite to coil inductance D. coil inductance discharge occurring at commutation

Last Answer : Answer: D

Name the materials used to insulate the laminations of the core of induction motor.

Description : Name the materials used to insulate the laminations of the core of induction motor.

Last Answer : The materials used to insulate the laminations are kaolin and varnish.

77 The transformer laminations are insulated from each other by A. Mica strip B. Thin coat of varnish C. Paper D. Any of the above

Description : 77 The transformer laminations are insulated from each other by A. Mica strip B. Thin coat of varnish C. Paper D. Any of the above

Last Answer : B. Thin coat of varnish

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

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

The degree of mechanical vibrations produced by the laminations of a transformer depends on?

Description : The degree of mechanical vibrations produced by the laminations of a transformer depends on?

Last Answer : The degree of mechanical vibrations produced by the laminations of a transformer depends on tightness of clamping, gauge of laminations, size of laminations.

The thickness of laminations used in a transformer is usually?

Last Answer : The thickness of laminations used in a transformer is usually 0.4 mm to 0.5 mm.

The transformer laminations are insulated from each other by?

Last Answer : The transformer laminations are insulated from each other by thin coat of varnish.

Stones are provided in the substation to: a) To avoid fire accident by draining oil from transformer if leaks b) To avoid growing of weeds and plants c) To provide insulation d) All the above

Description : Stones are provided in the substation to: a) To avoid fire accident by draining oil from transformer if leaks b) To avoid growing of weeds and plants c) To provide insulation d) All the above

Last Answer : Ans: D

Compare core type and shell type transformer.

Description : Compare core type and shell type transformer.

Last Answer : Shell Type Transformer Core Type Transformer The core surround the windings  The Winding surround the core Magnetic Flux is distributed into 2 paths  Magnetic Flux has only ... in Weight  Less in Weight  It has two windows opening  It has one window opening

State the advantages of amorphous core type distribution transformer.

Description : State the advantages of amorphous core type distribution transformer.

Last Answer : Advantages of amorphous core type distribution transformer: 1) Increases efficiency of transformer as constant losses are reduced by 75 % compared to conventional transformers. 2) The material has high ... . 7) High Reliability. 8) Excellent short circuit capacity. 9) Less maintenance cost.

The main purpose of using core in a transformer is to

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.

The primary turns of a 444 V/222 V, 50 Hz single-phase transformer with a core cross- sectional area of...

Description : The primary turns of a 444 V/222 V, 50 Hz single-phase transformer with a core cross-sectional area of 100 cm2, and a maximum flux density of 1.0 T is (A) 100 (B) 200 (C) 222 (D) 400

Last Answer : The primary turns of a 444 V/222 V, 50 Hz single-phase transformer with a core cross-sectional area of 100 cm2, and a maximum flux density of 1.0 T is 200

The core of a transformer (medium size) uses to provide high flux densities

Description : The core of a transformer (medium size) uses to provide high flux densities (a) diamagnetic (c) ferromagnetic core (b) paramagnetic (d) none of these

Last Answer : The core of transformer is made up colled rolled grain oriented. It is a ferromagnetic material..

The most suitable material for transformer core is

Description : The most suitable material for transformer core is  (1) hot rolled grain oriented steel (2) cold rolled grain oriented steel (3) aluminium (4) copper

Last Answer : cold rolled grain oriented steel

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

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

Last Answer : Transformer cores are laminated to reduce eddy current loss.

why the Transformer core is laminated?

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

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

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

The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor

Description : The air gap in an induction motor should be checked periodically with a feeler gage to detect ____________. A. rotor contact with the laminations B. changes in armature magnetic strength C. excessive bearing wear D. electrical damage to the rotor

Last Answer : Answer: C

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

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

In a series wound motor, the current passing through the field windings is also passing through the _____________. A. armature B. shunt field C. reactance comparator D. laminations

Description : In a series wound motor, the current passing through the field windings is also passing through the _____________. A. armature B. shunt field C. reactance comparator D. laminations

Last Answer : Answer: A

There are number of laminations in a (a) Close coiled spring (b) Open coiled spring (c) Spiral spring (d) None

Description : There are number of laminations in a (a) Close coiled spring (b) Open coiled spring (c) Spiral spring (d) None

Last Answer : (d) None

There are number of laminations in a (a) Close coiled spring (b) Open coiled spring (c) Spiral spring (d) None

Description : There are number of laminations in a (a) Close coiled spring (b) Open coiled spring (c) Spiral spring (d) None

Last Answer : (d) None

The thick shell is made from laminations to get (a) Increased stresses (b) Decreased stresses (c) Uniform stresses (d) None

Description : The thick shell is made from laminations to get (a) Increased stresses (b) Decreased stresses (c) Uniform stresses (d) None

Last Answer : (c) Uniform stresses

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

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

61 The degree of mechanical vibrations produced by the laminations of a transformers depends on A. Tightness of clamping B. Gauge of laminations C. Size of laminations D. All of the above

Description : 61 The degree of mechanical vibrations produced by the laminations of a transformers depends on A. Tightness of clamping B. Gauge of laminations C. Size of laminations D. All of the above

Last Answer : D. All of the above

60)The noise resulting from vibrations of laminations set by magnetic force, is termed as A. magnetostriction B. boo C. hum D. zoom

Description : 60)The noise resulting from vibrations of laminations set by magnetic force, is termed as A. magnetostriction B. boo C. hum D. zoom

Last Answer : C. Hum

The laminations of the armature of a D.C. machine are usually _____ thick. (a) 0.1 to 0.2 mm (b) 0.2 to 0.3 mm (c) 0.3 to 0.4 mm (d) 0.4 to 0.5 mm

Description : The laminations of the armature of a D.C. machine are usually _____ thick. (a) 0.1 to 0.2 mm (b) 0.2 to 0.3 mm (c) 0.3 to 0.4 mm (d) 0.4 to 0.5 mm

Last Answer : (d) 0.4 to 0.5 mm

Silicon steel used in laminations mainly reduces?

Last Answer : Silicon steel used in laminations mainly reduces hysteresis loss.

In single core cables armouring is not done to (a) avoid excessive sheath losses (b) make it flexible (c) either of the above (d) none of the above

Description : In single core cables armouring is not done to (a) avoid excessive sheath losses (b) make it flexible (c) either of the above (d) none of the above

Last Answer : (a) avoid excessive sheath losses

Why shading rings provided in armature core of ac contactor. Why not for dc contactor?

Description : Why shading rings provided in armature core of ac contactor. Why not for dc contactor? 

Last Answer : Because the force developed is not steady in ac therefore contacts will chatter but if shading ring is used force developed becomes steady due to splitting of phases of flux, therefore contacts becomes bounce free and humming sound reduces.  

In aluminium conductors, steel core is provided to (a) compensate for skin effect (b) neutralise proximity effect (c) reduce line inductance (d) increase the tensile strength

Description : In aluminium conductors, steel core is provided to (a) compensate for skin effect (b) neutralise proximity effect (c) reduce line inductance (d) increase the tensile strength

Last Answer : (d) increase the tensile strength

Of which irom is Core of transformer made up? -Do You Know?

Description : Of which irom is Core of transformer made up? -Do You Know?

Last Answer : answer:

What is the core of the transformer made of ?

Description : What is the core of the transformer made of ?

Last Answer : The core of the transformer is made of: The core of the transformer is usually made of a type of steel called silicon steel. Transformer cores are not usually made of normal stainless steel.

Why insulation or thin coating is used in the core of transformer ?

Description : Why insulation or thin coating is used in the core of transformer ?

Last Answer : In the core of a small transformer there are actually many ( E) and ( I) and different sized steel sheets of large size transformers. In fact, one type of varnish / lamination paint is applied on ... was a lot of voltage and drops. So insulation is used in the transformer to prevent this loss.

On what does the core loss of a transformer depend ?

Description : On what does the core loss of a transformer depend ?

Last Answer : The core loss of the transformer depends on the voltage applied to the primary.

What is a Core Type Transformer ?

Description : What is a Core Type Transformer ?

Last Answer : Answer : The core of this type of transformer is made up of a rectangular 'L' laminated steel sheet. It encloses most of the core space in the coils. Only one magnetic socket is made in the ... voltage windings are applied to the two opposite arms of such a core. It is called Core Type Transformer.

Of which irom is Core of transformer made up?

Description : Of which irom is Core of transformer made up?

Last Answer : – Soft iron

The harmonic currents in a power transformer does not cause increase in: a) Secondary voltage b) Core loss c) Copper loss d) Magnetic interference with protective relays

Description : The harmonic currents in a power transformer does not cause increase in: a) Secondary voltage b) Core loss c) Copper loss d) Magnetic interference with protective relays

Last Answer : Ans: A

The best material for the core of a transformer is – (1) stainless steel (2) mild steel (3) hard steel (4) soft iron

Description : The best material for the core of a transformer is – (1) stainless steel (2) mild steel (3) hard steel (4) soft iron

Last Answer : (4) soft iron Explanation: Iron has a very large magnetic response: it greatly amplifies an applied magnetic field. The transformer's ability to transfer energy depends on the strength of the magnetic ... field is amplified. The input energy can then be lower while still having the same effect.

Which of the listed electrical devices is represented by the symbol shown in the illustration? EL-0055 A. Fixed resistance resistor B. Coil with magnetic core C. DC motor or generator shunt field D. Transformer

Description : Which of the listed electrical devices is represented by the symbol shown in the illustration? EL-0055 A. Fixed resistance resistor B. Coil with magnetic core C. DC motor or generator shunt field D. Transformer

Last Answer : Answer: D

In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded for 10 minutes to remove static charges. B. The transformer connections must be made as before with regard to the indicated polarity. C. The iron core of the transformer must be flashed to pre-magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Description : In replacing a defective transformer with a new one, which of the following actions must be carried out to insure proper operation of the equipment it serves? A. The secondary leads must be grounded ... magnetize it. D. The iron core must be grounded for 10 minutes to remove any residual magnetism.

Last Answer : Answer: B

The hook-on AC volt-ammeter consists essentially of a split-core and a rectifiertype instrument connected to the secondary winding of a _____________. A. potential transformer B. control transformer C. current transformer D. reactance transformer

Description : The hook-on AC volt-ammeter consists essentially of a split-core and a rectifiertype instrument connected to the secondary winding of a _____________. A. potential transformer B. control transformer C. current transformer D. reactance transformer

Last Answer : Answer: C

When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil

Description : When a transformer is used to step down voltage, the low voltage winding is _____________. A. part of the core B. the primary coil C. not insulated D. the secondary coil

Last Answer : Answer: D

If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core

Description : If a transformer is connected to a DC source, the transformer will overload at the ____________. A. contacts B. primary coil C. secondary coil D. core

Last Answer : Answer: B

Figure 'B' shown in the illustration represents a/an ____________. EL-0091 A. magnetic amplifier B. Scott-T transformer C. saturable-core reactor D. oil-filled toroid

Description : Figure 'B' shown in the illustration represents a/an ____________. EL-0091 A. magnetic amplifier B. Scott-T transformer C. saturable-core reactor D. oil-filled toroid

Last Answer : Answer: A

Figure 'A' shown in the illustration represents a/an _______________. EL-0091 A. magnetic amplifier B. Scott-T transformer C. saturable-core reactor D. oil-filled toroid

Description : Figure 'A' shown in the illustration represents a/an _______________. EL-0091 A. magnetic amplifier B. Scott-T transformer C. saturable-core reactor D. oil-filled toroid

Last Answer : Answer: C

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

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.

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

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

Last Answer : In order to minimize eddy current loss.