If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
self excited generator must be started without any external load attached ,an external load will continuously drain off the build up voltage and prevent the generator from reaching its proper operating voltage. also the presence of residual magnetism plays an important role And the field current resistance should be less than critic field circuit resistance
no...because before producing voltage needed to connect the generator to the grid then after it will produced voltage.AnswerYes, but only if you have an external d.c. supply to supply the field windings. Such machines are called, 'separately-excited'.
It fails to build up because self excited DC motor's armature have only one direction of rotation. So that if the poles of the armature are reversed, then this causes the reduction in the residual magnetism and eventually, it will stop.
not without a permit
Voltage is a build up of electrons at one location relative to another location. To form a voltage gradient (difference), you need to somehow build up electrons at one location, or remove electrons from one location. Shuffling your feet on a thick carpet can do this!
List the factors that affect the voltage building in D.C generator.
yes
What can usually happen is the permanent magnets in the generator will become energized, and like static shocks, will store energy in them.
This case arises only in series dc generator current should be sent around the poles to magnetize. this current can the source(generator). current is passed through poles if it is loaded. but if it is not loaded current is zero through the field. load voltage should be zero actually.but this dont happen.we use generator frequently.due to this poles are partially magnetized this causes some voltage appear called residual voltageAnswerThere's no such thing as 'residual voltage'; you're confusing it with 'residual magnetism', which exists in the magnetic poles of a self-excited d.c. generator and which enables the build-up of its terminal voltage.
The value of resistance of shunt field winding beyond which the shunt generator fails to build up its voltage is known as " critical resistance at a given speed it is the maximum field resistance with which the shunt generator excite.
An electrostatic generator uses mechanical energy to separate positive and negative charges, creating a build-up of static electricity. This build-up can be stored in a capacitor and then discharged as a spark or electromagnetic radiation. The generator typically involves friction between two materials to transfer electrons and create a potential difference.
Michael Faraday was among the first to build an electric motor and a generator, laying the foundation for modern electromagnetic technology. Faraday's work on electromagnetic induction also led to the development of basic principles of the electric transformer.
self excited generator must be started without any external load attached ,an external load will continuously drain off the build up voltage and prevent the generator from reaching its proper operating voltage. also the presence of residual magnetism plays an important role And the field current resistance should be less than critic field circuit resistance
Induction ;)
If the rotation is reversed in DC generator the permanent magnetism already occurred for voltage build up process may demagnetize. this will causes no emf induce at starting time.The reversal of rotation is not affect externally excited generators
If there is no residual magnetism in the field poles then there would be no flux too induce the initial voltage for self exitation
no...because before producing voltage needed to connect the generator to the grid then after it will produced voltage.AnswerYes, but only if you have an external d.c. supply to supply the field windings. Such machines are called, 'separately-excited'.