Why does a transformer only work with an AC supply?

Why does a transformer only work with an AC supply?
by

3 Answers

Answer :

AC can produce changing magnetic field which is required for step up or step down purpose. Using that changing magnetic field it can generate changing voltage.

by

Answer :

When alternating voltage is connected to the primary side, a small current called magnetizing current will flow and an alternating magnetic field is set up in the core, this alternating field links with the secondary winding by mutual induction and an emf is produced. So with DC we can't have an alternating magnetic field that will link our windings, coz our voltage is direct isn't alternating
by

Answer :

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

Related questions

An AC supply of 230 V is applied to a half-wave rectifier circuit through a transformer having primary to

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 

Last 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 

Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is

Description : Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is

Last Answer : Total instantaneous power supplied by a 3-phase ac supply to a balanced R-L load is constant

Draw the waveform of three phase AC supply voltage.

Description : Draw the waveform of three phase AC supply voltage.

The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of

Description : The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz 

What will happen if the primary of a transformer is connected to D.C. supply?

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 

Last 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 

If the supply frequency to the transformer is increased, the iron loss will?

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

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

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?

Last 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.

If a D.C. series motor is operated on A.C. supply, it will?

Last Answer : If a D.C. series motor is operated on A.C. supply, it will spark excessively, have poor efficiency, have poor power factor.

To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that...

Description : To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken?

Last Answer : To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken from the same source as the unknown voltage.

Can transformer convert AC to DC?

Description : Can transformer convert AC to DC?

Last Answer : No, Transformer cannot convert AC to DC.

The instructions for starting the computer are house on a. Random access memory b. CD-Rom c. Read only memory chip d. All of above

Description : The instructions for starting the computer are house on a. Random access memory b. CD-Rom c. Read only memory chip d. All of above

Last Answer : c. Read only memory chip

How IGBT convert DC into AC in solar inverter?

Last 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.

The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a?

Last Answer : The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a two-phase winding.

State the modification to be done in dc series motor to work satisfactorily as ac series motor. State applications of ac series motor.

Description : State the modification to be done in dc series motor to work satisfactorily as ac series motor. State applications of ac series motor.

Last Answer : Modifications are necessary in a dc series motor so that it operates satisfactorily on ac supply. The modifications are as follows:  1) AC series motor is built with a few field turns as ... and grinders 5) High speed vacuum cleaners 6) Sewing machines 7) Food processors 8) Drilling machine 

What is need of regulated power supply?

Description : What is need of regulated power supply?

Last Answer : A regulated power supply is used to ensure that the output remains constant even if the input changes. But sometimes main supply voltage, load, and surrounding temperature keep changing and altering the ... power supply is needed that will accept an AC input and give a constant DC output.

Two 100W, 200V lamps are connected in series across a 200V supply. The total power

Description : Two 100W, 200V lamps are connected in series across a 200V supply. The total power consumed by each lamp will be in Watts

Last Answer : 4800

We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance

Description : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be

Last Answer : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be 2.4 kOhm

Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch

Description : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these

Last Answer : Consider a circuit with three parallel branches connected across a DC supply. What is the ratio of the branch currents I1 : I2 : I3 if the branch resistances are in the ratio of 2 : 3 : 4 respectively? A) 2 : 3 : 4 B) 6 : 4 : 3 C) 4 : 3 : 2 D) None of these

In a three-phase supply floating neutral is undesirable because it way give rise to?

Description : In a three-phase supply floating neutral is undesirable because it way give rise to?

Last Answer : In a three-phase supply floating neutral is undesirable because it way give rise to unequal line voltages across the load.

The effective resistance of an iron-cored choke working on ordinary supply frequency...

Description : The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of?

Last Answer : The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of iron loss in core.

How To Make An Emergency Supply Kit

Description : How To Make An Emergency Supply Kit

Last Answer : How To Make An Emergency Supply Kit Accidents and natural disasters happen; they are among the unavoidable and unpleasant occurrences that happen in life. Unfortunately, we can't predict when and ... emergency supply kit properly, and you'll be able to make it through the catastrophe unscathed.

Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life.

Description : Analyze the effect of supply voltage on performance of LED as regards current, Lumen output, efficacy and life. 

Last Answer : 1) Effect on Current:- In LED current depends upon supply voltage, if voltage get changes then current also change but this change in current will be control by resistors which are connected in series.  2) ...   4) Effect on Life:- If supply voltage is not stable then life of LED get reduced. 

Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Description : Draw the block diagram of regulated power supply, explain function of each block and draw waveforms of each stage.

Last Answer : 1. A step down transformer 2. A rectifier 3. A filter 4. A regulator Operation of Regulated Power Supply:- Step Down Transformer:- A step down transformer will ... regulator. A regulator will maintain the output constant even when changes at the input or any other changes occur.

Define phase sequence of three phase supply with waveforms.

Description : Define phase sequence of three phase supply with waveforms. What is normal phase sequence? Which 3 standard colours are used to denote the phase sequence?

Last Answer : It  is  sunnosoidal  sequence.

Define balanced supply and unbalanced supply.

Description : Define balanced supply and unbalanced supply.

What is the Power Supply specification for 8085AH microprocessor?

Description : What is the Power Supply specification for 8085AH microprocessor? A) Single +5V supply with 10% voltage margins B) Dual +5V supply with 10% voltage margins C) Single +10V supply with 5% voltage margins D) Dual +5V supply with 5% voltage margins 

Last Answer : What is the Power Supply specification for 8085AH microprocessor? A) Single +5V supply with 10% voltage margins B) Dual +5V supply with 10% voltage margins C) Single +10V supply with 5% voltage margins D) Dual +5V supply with 5% voltage margins 

A change of 4% in the supply voltage to an induction motor will produce a change of approximately

Description : A change of 4% in the supply voltage to an induction motor will produce a change of approximately

Last Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque

The supply for arc welding is :

Description : The supply for arc welding is : 

Last Answer : The supply for arc welding is : Low voltage, high current ac or dc voltage

The time period of third harmonic of power supply frequency, in milliseconds, is

Description : The time period of third harmonic of power supply frequency, in milliseconds, is (A) 20 (B) 3.33 (C) 6.66 (D) 60

Last Answer : The time period of third harmonic of power supply frequency, in milliseconds, is 6.66 

While keeping the excitation constant, if the steam supply of an alternator running in parallel with another

Description : While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then (A) It would over-run the other alternator (B) Its rotor ... (C) Its portion of share in load will increase (D) Its power factor would be decreased.

Last Answer : While keeping the excitation constant, if the steam supply of an alternator running in parallel with another identical alternator is increased, then Its portion of share in load will increase

Overhead lines for power supply to tramcars are at a minimum height of?

Last Answer : Overhead lines for power supply to tramcars are at a minimum height of 10 m.

A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by...

Description : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will?

Last Answer : A capacitor-start single phase induction motor is switched on to supply with its capacitor replaced by an inductor of equivalent reactance value. It will not start at all.

If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then?

Last Answer : If the synchronous motor, properly synchronised to the supply is running on no load and is having negligible loss then the stator current will be zero.

The primary reason for low power factor is supply system is due to installation of?

Last Answer : The primary reason for low power factor is supply system is due to installation of induction motors.

For high value of diversity factor, a power station of given installed capacity will be in a position to supply?

Last Answer : For high value of diversity factor, a power station of given installed capacity will be in a position to supply more number of consumers.

why rectifier is used in power supply ?

Last Answer : Rectifier is use in power supply to convert Alternating current (AC) to Direct Current (DC) .

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

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

why transformer don't work on DC supply?

Description : why transformer don't work on DC supply?

Last Answer : 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.

The maximum constant load torque under which a synchronous motor will pull into synchronism...

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.