why transformer don't work on DC supply?

2 Answers

DC can not produce changing magnetic flux that's why.

Like 0 like Dislike 0 dislike
A  DC  current  does  not  produce  a  changing  magnetic   field   which  is   capable  of  inducing   current   on   the   secondary    windings   of   a   transformer   through  mutual   induction   process.
Like 0 like Dislike 0 dislike

Related questions

Description : Why does a transformer only work with an AC supply?

Answer : The transformer work depends on the induction as main principle ,for that AC is the right means

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

Answer : At 0.866 time voltage value

Description : Write about transformer on DC.

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 : What will happen if the primary of a transformer is connected to D.C. supply?  (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn 

Answer : What will happen if the primary of a transformer is connected to D.C. supply?  (A) Transformer will operate with low efficiency (B) Transformer will operate with high efficiency (C) No effect (D) Transformer may start to smoke and burn 

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

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

Description : Transformer generally rated in KVA

Answer : The power of transformer is apparent power because it has no power factor and it is the product of voltage and current.

Answer : The efficiency of transformer is Greater than electrical Machine because there is no rotational losses in transformer and there is no air gap losses in transformer so losses is less in transformer compare to electrical machine so efficiency is higher in case of transformer.

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

Description :  An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V 

Answer :  An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to secondary turn’s ratio 12:1. The peak inverse voltage is A) 8.62 V B) 12 V C) 19.17 V D) 27.11 V 

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.

Answer : If the supply frequency to the transformer is increased, the iron loss will increase.

Description : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of?

Answer : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of less than 15A.

Description : Can transformer convert AC to DC?

Answer : No, Transformer cannot convert AC to DC.

Description : What is a transformer and how does it work?

Answer : A transformer is an electrical apparatus designed to convert alternating current from one voltage to another. It can be designed to step up or step down voltages and works on the magnetic ... or voltage ratio) between the primary and secondary depends on the turns ratio of the two coils.

Description : Why power is constant in a transformer

Description : State why a transformer always have an efficiency of more than 90%.

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 : Even at no-load, a transformer draws current from the mains. Why?

Description : Why Transformer rating is given in kVA?

Answer : 1) The output of transformer is limited by heating due to the losses. Two types of losses in the transformer (i) Iron loss, (ii) Copper loss. 2) Iron loss depends on the transformer voltage (V). ... by load power factor. - Hence the transformer output is expressed in VA or kVA and not in kW.

Description : Explain the procedure to perform Short Circuit test on single phase transformer with circuit diagram.

Description : Compare RC coupled, transformer coupled and direct coupled amplifier based on four points.

Answer : Parameter RC coupled Transformer coupled Direct coupled  Coupling element Resistor and capacitor Transformer No element Impedance matching Poor Excellent good Frequency ... Low frequency amplifier,opamp Size and cost small Large and bulky least

Description : The transformer works on the principle of: (A) Mutual induction (B) Mutual capacitance (C) All of the above (D) None of the above

Answer : The transformer works on the principle of:  Mutual induction

Description : Increasing the number of turns of wire on the secondary of a transformer will  (A) Decrease the secondary current (B) Increase the primary current (C) Have no effect on the secondary current (D) Increase the secondary current

Answer : Increasing the number of turns of wire on the secondary of a transformer will Decrease the secondary current 

Description : What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage:  (A) Eddy Current and Hysteresis losses will be ... Current will be too much high  (C) Transformer may start to smoke and burn  (D) No effect

Answer : What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage:  (A) Eddy Current and Hysteresis losses will be ... will be too much high  (C) Transformer may start to smoke and burn  (D) No effect

Description : Can a Single Phase Transformer be used on a Three Phase source?

Answer : Yes. Any single phase transformer can be used on a three phase source by connecting the primary leads to any two wires of a three phase system, regardless of whether the source is three phase 3-wire or three phase 4-wire. The transformer output will be single phase.

Description : Explain the effect of Harmonics on the Transformer.

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 : Explain the open delta (delta-delta) test on transformer.

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

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

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

Description : An open-circuit test on a transformer is conducted primarily to measure?

Answer : The open-circuit test in a transformer is used to measure

Description : A no-load test is performed on a transformer to determine?

Answer : A no-load test is performed on a transformer to determine magnetizing current and loss.

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

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

Description : Sumpner's test is conducted on transformer to determine?

Answer : Sumpner's test is conducted on transformer to determine temprature.

Answer : Igbt alone cant convert dc to ac. igbt half bridge or full bridge or three phase topology could be used to convert dc to ac. also igbt gates should be driven by microcontroller or pwm/spwm gate driving signals ... e4(-) and g4 c2e1 and c4e3 pins are AC output pins. its name is igbt inverter.

Description : What is the back E.M.F in Transformer ?

Answer : Back emf in transformer is when apply voltage in primary side of transformer. This voltage produce flux according to Faraday law electro magnetic induction. This flux called mutual flux and this ... secondary flux oppos the applied voltage according to lenz law. its called back emf of transformer

Description :  transformer coupled amplifier

Answer :  transformer coupled amplifier

Description : Transformer efficiency

Answer : Transformer efficiency

Description : Explain construction and working of isolation transformer.

Answer :  Isolation Transformer https://youtu.be/gq9kjLlhPN0

Description : Write selection criteria of distribution transformer with any four points.

Answer : Selection Criteria for Distribution Transformer:  i) Ratings - The kVA ratings should comply with IS:2026 ( Part l )-1977*. The noload secondary voltage should be 433 volts for transformers to be ... is not necessary. vi) Cooling - The transformers covered in this group are generally ONAN, AN

Description : Write any four advantages of instrument transformer.

Answer : Advantages of instrument transformer: 1. Extension of instrument range is possible. 2. Isolation of instruments from high voltage side. 3. Power loss is less as compared to shunts and multipliers. 4 ... measurement. 5. It is economical method of range extension. 6. Increases in safety of operator.

Description : State the advantages of instrument transformer in using for extension of range of meters. 

Answer : Advantages of instrument transformer: 1. Extension of instrument range is possible. 2. Isolation of instruments from high voltage side. 3. Power loss is less as compared to shunts and multipliers. 4 ... measurement. 5. It is economical method of range extension. 6. Increases in safety of operator.

Description : Introduction to transformer

Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed ... power start transformer, autotransformer, multiphase transformer, magnetic flux linkage transformer, resonant transformer etc.

Description : Cylindrical type transformer has:  (A) Single magnetic circuit (B) Double magnetic circuit (C) All of the above (D) None of the above

Answer : Cylindrical type transformer has: Single magnetic circuit

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

Answer : The rating of transformer may be expressed in kVA . 

Description : Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines:  (A) Delta-Star (B) Star-Delta (C) Delta-Delta (D) Star-Star

Answer : Which of the following 3-phase connection of a transformer causes interference with the neighbouring communication lines: Star-Star

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

Answer : Which of the following does not change in a transformer?  (A) Current (B) Voltage (C) Frequency (D) All of the above

← Prev Question Next Question →
Ask a Question
Choose topic