1 Answer

Answer :

A transformer can have regulation closer to zero on leading power factor.

Related questions

Description : A good voltage regulation of a transformer means?

Last Answer : A good voltage regulation of a transformer means output voltage fluctuation from no load to full load is least.

Description : A ferro resonant transformer regulation is also known as?

Last Answer : A ferro resonant transformer regulation is also known as constant current transformer.

Description : A transformer has negative voltage regulation when its load power factor is   (1) Zero (2) Unity (3) Leading (4) Lagging

Last Answer : 0

Description : Negative voltage regulation is indicative that the load is?

Last Answer : Negative voltage regulation is indicative that the load is capacitive.

Description : Minimum voltage regulation occurs when the power factor of the load is?

Last Answer : Minimum voltage regulation occurs when the power factor of the load is leading.

Description : Which of the following has nearly zero temperature coefficient? A) Constantan B) Manganin C) Both A and B D) None of these

Last Answer : Which of the following has nearly zero temperature coefficient? A) Constantan B) Manganin C) Both A and B D) None of these

Description : ln HRC fuse the time between cut-off and final current zero is called

Last Answer : ln HRC fuse the time between cut-off and final current zero is called the arcing time

Description : Is electric potential zero when electric field is zero?

Last Answer : Yes  .If  electric  field  is  zero  then  electric  potential  is  zero  ,  not  even  one.

Description : Can the electric field between two positive charges be zero?

Last Answer : It  can  only  if  they  have  equal  charges.

Description : Define line regulation and load regulation.

Last Answer : Load regulation is the ability of the power supply to maintain its specified output voltage over changes in the load. Line regulation is the ability of the power supply to maintain its specified output voltage over changes in the input line voltage.

Description : Classify hydro-electric power plants according to water flow regulation and explain in brief.

Last Answer : Classification of hydro-electric power plants according to water flow regulation of water flow:-  1. Large reservoir power plant 2. Run-off river (ROR) power plant with poundage 3. Run-off River ... depends upon rate of flow of water Initial cost is less Its purpose is to generate electricity.

Description : Define load and line regulation.

Last Answer : 1. Load regulation : The load regulation indicates how much the load voltage changes when the load current changes. The load regulation is defined as:  % Load regulation = (VNL-VFL) / VFL *100  ... the power supply. A well-regulated power supply can have a line regulation of less than 0.1%.  

Description : Identify the increasing order of voltage regulation of the following dc generators a same load :  (A) differential compound, shunt and under compound  (B) shunt, differential compound and ... C) under compound, shunt and differential compound  (D) shunt, under compound and differential compound

Last Answer : Identify the increasing order of voltage regulation of the following dc generators a same load : under compound, shunt and differential compound 

Description : The unit of speed regulation of a governor is :  (A) Hz (B) Hz/MW (C) Hz/MVA (D) rpm/MVAR

Last Answer : The unit of speed regulation of a governor is : Hz/MW

Last Answer : The voltage regulation in magnetic amplifier type voltage regulator is effected by varying the reactance.

Description : State and justify which of the following two transformers is better:  Transformer A = 4% voltage regulation  Transformer B = 6% voltage regulation

Last Answer : Transformer A with 4% voltage regulation is better.  Justification: Voltage regulation refers to the percentage change in secondary voltage when load is changed from no-load to full-load with primary voltage ... 4% voltage regulation, which is less as compared to 6% of transformer B, it is better.

Description : 51 A transformer has negative voltage regulation when its load power factor is A. Zero B. Unity C. Leading D. Lagging

Last Answer : C. leading

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.

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

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.

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%.

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

Description : Single phase transformer

Last Answer : Single phase Transformer Transformer

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. 

Description : Write about transformer on DC.

Last Answer : Transformer on DC : Transformer cannot work on DC. Transformer works on electromagnetic induction principle. Electromagnetic induction principle means when flux linking with coil changes and EMF induced in it ... winding insulation will burn. https://youtu.be/TVp_0fIfxqY

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 : Explain construction and working of single phase Auto transformer.

Last Answer : Construction of single phase auto transformer: (i) It has only one winding wound on a laminated circular magnetic core. (ii) The core is made of silicon steel stampings. (iii) The two terminals of the ... help of handle. 5) The same transformer can be used as step-up or step down auto-transformer

Last Answer : No-load current in a transformer lags behind the voltage by about 75°.

Last Answer : The purpose of providing an iron core in a transformer is to decrease the reluctance of the magnetic path.

Last Answer : In the transformer low voltage winding has got more cross-sectional area.

Last Answer : A transformer cannot raise or lower the voltage of a D.C. supply because Faraday's laws of electromagnetic induction are not valid since the rate of change of flux is zero.

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

Last Answer : High voltage winding in a transformer has more number of turns.

Last Answer : The efficiency of a power transformer is of the order of 98 percent.

Last Answer : The no load current in a transformer lags behind the applied voltage by an angle of about 75°.

Last Answer : In a transformer, routine efficiency depends upon load current and power factor of load.

Last Answer : The maximum efficiency of a distribution transformer is at 50% full load.

Last Answer : Transformer breaths in when load on it decreases.

Last Answer : No-load current of a transformer has small magnitude and low power factor.

Last Answer : The purpose of providing iron core in a step-up transformer is to decrease the magnitude of magnetizing current.

Last Answer : The power transformer is a constant main flux device.

Last Answer : In a transformer, the tappings are generally provided on low voltage side.

Last Answer : The use of higher flux density in the transformer design reduces weight per kVA.

Last Answer : The chemical used in breather for transformer should have the quality of cleansing the transformer oil.

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

Last Answer : The transformer ratings are usually expressed in terms of kVA.

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

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

Last Answer : conservator or a reservoir tank for insulating oil in transformer which used for balanced the onload oil level with help of oil level indicator which mount on middle part of reservoir tank.

Last Answer : A transformer oil must be free from moisture.