What is impulse voltage of transformer?

Related Questions

Description : What is a switching impulse?

Description : What is the impulse response of the system?

Description : Step-down transformer converts high voltage and low current into:  (A) How voltage and high current (B) High voltage and low current (C) Low voltage and high current (D) None of the above

Last Answer : Step-down transformer converts high voltage and low current into: Low voltage and high current

Description : 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

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

Last Answer : Leading

Description : What is a capacitor voltage transformer? A) It is a transformer used in power systems to step up low voltage signals and provide extra high voltage B) It is a transformer used in power systems ... in power systems to step down extra high voltage signals and provide low voltage D) None of these

Last Answer : What is a capacitor voltage transformer? A) It is a transformer used in power systems to step up low voltage signals and provide extra high voltage B) It is a transformer used in power systems ... power systems to step down extra high voltage signals and provide low voltage D) None of these

Description : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?

Last Answer : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are hysteresis and eddy current losses.

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 : The voltage transformation ratio of a transformer is equal to the ratio of?

Last Answer : The voltage transformation ratio of a transformer is equal to the ratio of secondary induced e.m.f. to primary induced e.m.f.

Description : If a transformer is switched on to a voltage more than the rated voltage?

Last Answer : If a transformer is switched on to a voltage more than the rated voltage its power factor will deteriorate.

Last Answer : yes High Voltage side of Transformer winding have more number of turns. and low voltage side of Transformer winding have less number of turns.

Description : In voltage source converter based HVDC transmission system the active power is controlled by changing (A) phase angle of the converter ac input voltage (B) supply frequency of the converter ac input voltage (C) magnitude of the converter ac input voltage (D) DC voltage at the inverter terminals

Last Answer : In voltage source converter based HVDC transmission system the active power is controlled by changing phase angle of the converter ac input voltage

Description : How do you fix voltage drop?

Description : What is meant by flash over voltage?

Description : Why high voltage test is done?

Description : What is dielectric withstand voltage?

Description : Why high voltage can reduce power loss?

Last Answer : when voltage has increased due to reduced current flow, thus power loss given by ( I^2R) will be low due to reduced current(I^2) provided that resistance (R) is constant.

Description : Why does increase in current mean a decrease in voltage?

Last Answer : This is because current flows from high potential to low potential to bring the two diffrent potential to unity , thus  a reduced potential (voltage)

Description : What is the definition of extra low voltage?

Last Answer : Extra-low voltage (ELV) is an electricity supply voltage in a range which carries a low risk of dangerous electrical shock.

Description : What is the difference between line and phase voltage?

Last Answer : Line voltage  is  voltage  between two  phases R &Y  (415 v)  while  phase  voltage  is  the  voltage  between  one  phase and  a neutral  B &  N   (240 v).

Description : What is Extra High Voltage?

Description : Why high voltage is used in power transmission?

Last Answer : The primary reason that power is transmitted at high voltages is to increase efficiency. ... The lower current that accompanies high voltage transmissionreduces resistance in the conductors aselectricity flows ... This means that thin, light-weight wires can beused in long-distance transmission.

Description : What is the difference between a line voltage and low voltage control system?

Description : What are the advantages of high voltage transmission?

Last Answer : Advantages:  1. As Transmission voltage increases, current decreases. 2. As current decreases, cross section of conductor decreases. 3. As cross section of conductor decreases ... line increases  12. As transmission voltage increases power handling capacity of transmission line increases 

Description : What is a high voltage test?

Description : What is considered low voltage and high voltage?

Description : 66 While conducting short-circuit test on a transformer the following side is short circuited A. High voltage side B. low voltage side C. primary side D. secondary side

Last Answer : B. Low voltage side

Description : 65)No-load current in a transformer A. Lags behind the voltage by about 75 deg B. leads the voltage by about 75 C. lags behind the voltage by about 15 D. leads the voltage by about 15

Description : 56 Which of the following does not change in a transformer? A. Current B. Voltage C. Frequency D. All of the above

Last Answer : C. Frequency

Description : 4] In operating a 400hz transformer at 50Hz A. Only voltage is reduced in the same proportion as the frequency B. Only KVA rating is reduced in the same proportion as the frequency C. Both voltage and KVA rating are reduced in the same proportion as frequency D. None of the above

Last Answer : B. Only KVA rating is reduced in the same proportion as the frequency

Description : 52 A transformer has 1000 primary turns, connected to 250V ac supply. To get 400V secondary voltage the no of secondary turns should be A. 1600 B. 250 C. 400 D. 1250

Last Answer : A. 1600

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 : 30 In performing the short circuit test of a transformer A. high voltage is usually short circuited B. low voltage side is usually short circuited C. any side is short circuited with preference D. none of the above

Last Answer : B. Low voltage side is usually short circuited

Description : 29.In transformer terminology, the ratio 20:1 indicates that A. there are 20 turns on primary one turn on secondary B. secondary voltage is 1/20th of the primary C. primary current is 20 times greater than the secondary current D. for every 0 turns on primary, there is one turn on secondary

Last Answer : B. Secondary voltage is 1/20 of the primary

Description : 25 A step up transformer increases A. voltage B. current C. power D. frequency

Last Answer : A. Voltage

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 : 16.step-up transformer increases A. voltage B. current C. power D. frequency

Last Answer : A. Voltage

Description : The frequency of the secondary voltage of a transformer will be..... A. less than frequency of the primary voltage B. equal to the primary voltage C. greater than the frequency of the primary voltage D. much greater than the frequency of the primary voltage

Last Answer : B. Equal to the primary voltage

Description : 10) A transformer transform a) frequency b) voltage c) current d) Voltage and current

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

Description : During short circuit test iron losses are negligible because A. The current on secondary side is negligible B. The voltage on secondary side does not vary C. The voltage applied on primary side is low D. Full-load current is not supplied to the transformer

Last Answer : C) the voltage applied on primary side is low

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 : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he

Last Answer : A single phase transformer has resistance and reactance of 0.2 pu and 0.6 pu respectively. Its pu voltage regulation at 0.8 pf lagging would he 0.52

Description : The inrush current of a transformer at no load is maximum if the supply voltage is switched on  (1) at peak voltage value (2) at zero voltage value (3) at half voltage value (4) at 0.866 time voltage value

Last Answer : At 0.866 time voltage value

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

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

Last Answer : When a given transformer is run at its rated voltage but reduced frequency, its core flux density is increased.

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