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Why is generator armature harder to rotate when it is connected to a circuit and supplying electric current?
Wiki User
∙ 12y ago
Because a generator extracts energy from whatever is rotating it and passes this (by the electric current it produces) down the circuit to the motor (or light bulb or heater) where it is used. When there is no complete electric circuit, no electricity can flow so no (little) energy is extracted, but when the circuit is closed, electricity does flow and the armature is more difficult to turn.
Wiki User
∙ 16y ago
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What are field windings and armature windings in a dc motor and generator?
generators have two types of winding , * at armature also called armature winding( winding around shaft , we can say), which is the moving part. note that armature also consists of magnets along with windings. hence produces field arount it. * and at stator also called field winding, because when armature rotates its flux(field) is cutted by the stator windings and produces mutually induced e.m.f in it( in stator windings off course) causing current to flow. this current also produces some electric field around it which is in return cutted by the armature windings hince a little amount of e.m.f ( also called back e.m.f) produced in armature due to stator winding current. know this current in armature (due to back e.m.f produced by stator winding) produces additional field , hence causing more current in stator winding. this is the reason that why stator windings are called field winding( as they cause electric field of armature stronger and cause more current in output). note that out put is taken from the stator windings in generators.
Working principle of generator?
An electric generator is a device which converts mechanical energy to electric energy. An electric generator basically works on two principles, they are:- 1. Electro magnetic induction: This was first discovered by Michael Faraday this law states that when a electric conductor moved through a magnetic field cutting the electro magnetic waves, a electric charge is produced in the conductor. 2. Flemming's right hand rule: Place your thumb finger, index finger, and your middle finger in such a way that all the three are mutually perpendicular to each other. Here if your thumb points the thrust or force and index finger points the electro magnetic field then your middle finger points the direction of induced current. An electric generator consists of a electromagnet or a huge horse shoe magnet in which an armature is enclosed. The armature is made of copper coils. Now when the armature is rotated, it cuts the electro magnetic waves generated by the magnet and hence as a result of electro magnetic induction electricity is generated in the armature and the direction of the induced current can be found out using the Flemming's Right Hand Rule. And how the electric current produced later is stored and carried out differentiates between AC generator and DC generator
How differential generator is used for electric arc welding process?
in welding sometimes your electrode got stuck to your work piece so a very high current would flow and no voltage at generator teminals. only a small voltage will produce in the armature due the residual magnetism in the machine itself. The only type dc machine that can operate satifactorily in this situation is a shunt connected dc genrator. This type of generator can run and exceed it full load current. if it allows to run beyond its rated load or its loads becomes zero ohms, then this machine is able to take up that load.(short ccit condition) So in differential generator to make it use for electric arc welding, just simply short out the series winding so there would be no flux induced or produced in it. only the current flows through the shunt winding.This time the generator is now running as a normal shunt connected dc generator. voltage output can be adjusted/varied by means of rheostat connected in series with it and armature.
How the generator and motor works ALTERNATING CURRENT GENERATORS BASIC AC GENERATORS Regardless of size all electrical generators whether dc or ac depend upon the principle of magneticinduction.?
An emf is induced in a coil as a result of (1) a coil cutting through a magnetic field, or (2) a magnetic field cutting through a coil. As long as there is relative motion between a conductor and amagnetic field, a voltage will be induced in the conductor. That part of a generator that produces the magnetic field is called the field. That part in which the voltage is induced is called the armature. Forrelative motion to take place between the conductor and the magnetic field, all generators must have two mechanical parts - a rotor and a stator. The ROTor is the part that ROTates; the STATor is the part that remains STATionary. In a dc generator, the armature is always the rotor. In alternators, the armature may be either the rotor or stator. ROTATING-ARMATURE ALTERNATORSThe rotating-armature alternator is similar in construction to the dc generator in that the armature rotates in a stationary magnetic field as shown in figure 3-1, view A. In the dc generator, the emf generated in the armature windings is converted from ac to dc by means of the commutator. In the alternator, the generated ac is brought to the load unchanged by means of slip rings. The rotating armature is found only in alternators of low power rating and generally is not used to supply electric power in large quantities.
What is a backwards working electric motor described as?
Electric Generator. :)
What are the effect of armature reaction in DC machine and how the armature reaction is minimise?
Armature reaction is the interaction between the magnetic flux produced by armature current and that of the main magnetic field in an electric motor or generator.
Why is armature connected to a sprinngy steel strip?
In an electric bell, a flat steel spring brings the armature back to its original position.
How is alternating current produced in a generator?
In an AC generator an armature is rotated in a magnetic field. This induces an electric current in the armature. if you want more look on the bottom. As the crank turns the armature rotates in the magnetic field. One side of the armature moves up, and the other side moves down. The up and down motion induces a current in the wire. The current is in opposite directions on two sides of the armature. After the armature turns halfway, each side of it reverses direction in the magnetic field. The side that moved up moves down, vice versa. The current is induced. As the Armature turns, slip rings turn with it. They are attached to the ends of the armature. As they turn, they make contact with the brushes. The brushes can be connected to the rest of the circuit. In this way, a generator becomes energy source.
A 105V generator delivers 25KW to an electric furnace What current is the generator supplying?
Power = E I25,000 = 105 II = 25,000 / 105 = 238.1 Amp
Operation of DC generator?
1) PRINCIPLE:Whenever a conductor cuts magnetic flux, dynamically induced emf is produced in it. ( Faraday's Laws of Electromagnetic Induction ). This emf causes a current to flow if the conductor circuit is closed.2 ) OPERATION:Field winding produces magnetic field in D.C. generator. Armature is coupled to the prime mover. Prime mover produces torque so the armature rotates. The armature cuts the magnetic field so the emf is induced in the armature. When load is connected to the armature, electric current flows from the armature conductors, through load and back to the armature conductors. Now, as current flows through the armature and it is in the magnetic field, torque is produced due to it. (This torque is called back torque). If the load on the generator is increased, the back torque increases so the torque of the prime mover also increases and the input power to the prime mover increases. In this way, the generator converts mechanical energy into electrical energy.It should be observed that the emf induced in D.C. generator, is A.C. ( so the emf induced in the armature is alternating in nature. ). Then with the help of commutator, it is converted into D.C. Rings and brushes are used to take the emf outside.
What type of electric energy turns a turnbine?
The turbine is turned by steam and is connected to a generator
Correct definition of the term armature?
The rotating coil of a dynamo or electric motor is called armature.
What is electromagnet in an electric motor called?
armature..!
Will a backup generator run my household?
A backup generator is used in cases of electricity power outages. The generator can be connected to your electric service and will power the electricity for a number of hours. To hook up a backup generator it would be advisable to hire a professional electrician.
What devices use magnets to create electricity?
An electrical generator. A microphone. A jet engine vibration detector. It has a magnet moving inside a bobbin with wire wrapped around it. An electric guitar pick up. A tape recorder head. A solar powered Sterling engine. The piston is a magnet and it passes through a coil. A few more.
What is an armature made of?
The armature is the part of an electric generator or motor that contains the main current-carrying winding. It usually consists of a coil of copper wire that is wound around an iron or steel core. The coil and core are placed in a magnetic field, which is produced by one or more permanent magnets or electromagnets.
What are field windings and armature windings in a dc motor and generator?
generators have two types of winding , * at armature also called armature winding( winding around shaft , we can say), which is the moving part. note that armature also consists of magnets along with windings. hence produces field arount it. * and at stator also called field winding, because when armature rotates its flux(field) is cutted by the stator windings and produces mutually induced e.m.f in it( in stator windings off course) causing current to flow. this current also produces some electric field around it which is in return cutted by the armature windings hince a little amount of e.m.f ( also called back e.m.f) produced in armature due to stator winding current. know this current in armature (due to back e.m.f produced by stator winding) produces additional field , hence causing more current in stator winding. this is the reason that why stator windings are called field winding( as they cause electric field of armature stronger and cause more current in output). note that out put is taken from the stator windings in generators.
