Please Log in or Register for more.


318 views

1 Answer

Answer :

The transformer ratings are usually expressed in terms of kVA.

Like 0 like

Please log in or register to answer this question.

Related Questions


The rating of transformer may be expressed in ____________.  (A) kVAR (B) kW (C) kVA (D) Horse power
Last Answer : The rating of transformer may be expressed in kVA . 

Show More

614 views 1 answer







Why Transformer rating is given in kVA?
Last Answer : Because of core losses and iron losses as core losses are measured in amps and cu losses in voltage ....this is definatly reason for the rating Or kVA is the unit for apparent power. Apparent ... shift between voltage and current). So a transformer has to be rated (and selected) by apparent power.

Show More

2.8k views 6 answers







Define kVA rating of transformer.
Last Answer : kVA rating of transformer is defined as the product of voltage (V) and current (I) on primary side of transformer or secondary side of transformer divided by 1000. On both side the VA rating remains ... Mathematically kVA rating is given by, kVA rating of transformer = V1I1/1000 =V2I2/1000

Show More

158 views 1 answer







The kVA rating of Three-phase transformer with Voltage = 200V and Current = 100A will be :  (A) 34.64 kVA (B) 75 kVA (C) 20 kVA (D) None of the above
Last Answer : The kVA rating of Three-phase transformer with Voltage = 200V and Current = 100A will be : 34.64 kVA

Show More

199 views 1 answer







The transformer ratings are usually expressed in terms of A. Volts B. Amperes C. kW D. kVA
Last Answer : D) KVA

Show More

113 views 1 answer








Last Answer : The fuse rating is expressed in terms of current.

Show More

151 views 1 answer







Boiler rating is usually defined in terms of  (1) Maximum temperature of steam in Kelvin (2) Heat transfer rate in KJ/hr (3) Heat transfer area in metre2 (4) Steam output in kg/hr
Last Answer : Boiler rating is usually defined in terms of Steam output in kg/hr

Show More

212 views 1 answer








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

Show More

241 views 1 answer








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

Show More

98 views 1 answer








Last Answer : Gas is usually not liberated due to dissociation of transformer oil unless the oil temperature exceeds 150°C.

Show More

195 views 1 answer








Last Answer : The magnetising current of a transformer is usually small because it has small air gap.

Show More

78 views 1 answer








Last Answer : The core used in high frequency transformer is usually air core .

Show More

213 views 1 answer







Where would you rate Ronald Reagan among US Presidents?
Last Answer : I think the “fat little dutchman” did good, made me laugh on numerous occasions.

Show More

0 views 1 answer







On a scale from 0 to 10, how do you rate the numbers in that scale?
Last Answer : 1: 1 2: 2 3: 3 4: 4 5: 7 6: 5 7: 6 8: 10 9: 8 10: 9

Show More

1 view 1 answer







How rating of main switch and cable is selected for Industrial Installation.
Last Answer : 1. Rating of Main Switch or Fuse Rating is decided in industrial installation: Rating of main switch or fuse is based up the starting current of motor. For calculating starting current is considered 2 ... take 1.5 times the rated current or full load current. & thus cable rating is decided.

Show More

325 views 1 answer








Last Answer : For the same H.P. rating and full load speed, following motor has poor starting torque differentially compounded.

Show More

164 views 1 answer








Last Answer : The wattage rating for a ceiling fan motor will be in the range 50 to 150 W .

Show More

177 views 1 answer







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.

Show More

127 views 1 answer







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

Show More

146 views 1 answer







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.

Show More

54 views 1 answer







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%.

Show More

262 views 1 answer







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

Show More

381 views 2 answers







Single phase transformer
Last Answer : Single phase Transformer Transformer

Show More

260 views 1 answer







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. 

Show More

159 views 1 answer







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

Show More

248 views 1 answer













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.

Show More

178 views 1 answer







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.

Show More

132 views 1 answer







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

Show More

344 views 1 answer








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

Show More

90 views 1 answer








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

Show More

202 views 1 answer








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

Show More

256 views 1 answer








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.

Show More

344 views 1 answer








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

Show More

86 views 1 answer








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

Show More

361 views 1 answer








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

Show More

99 views 1 answer








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

Show More

188 views 1 answer








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

Show More

133 views 1 answer








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

Show More

139 views 1 answer








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

Show More

90 views 1 answer








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

Show More

72 views 1 answer








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

Show More

545 views 1 answer








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

Show More

63 views 1 answer








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

Show More

92 views 1 answer








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

Show More

126 views 1 answer








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

Show More

187 views 1 answer








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

Show More

324 views 1 answer








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.

Show More

177 views 3 answers








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

Show More

68 views 1 answer








Last Answer : The main reason for generation of harmonics in a transformer could be saturation of core.

Show More

128 views 1 answer






Show More⇦ PreviousNext ⇨