poles are partially magnetized this causes some voltage called residual voltage
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.
In any DC generator the causes to fail to produce voltage is loss of residual flux in the field or fields , poor brush contact in the commutator(clean the brushes and commutator) , check all the terminals of the generator and voltmeter may not be functioningand lastly check the coupling and the prime mover is rotating.
It is the process of conversion of generated ac voltage into the armature of a dc generator to dc voltage at the terminal of the dc generator by use of pair of brushes and commutator. OR It is the process of conversion of given dc voltage at the terminal of the dc motor to ac voltage in the armature windings in a dc motor by use of pair of brushes and commutator.
A generator needs to have residual magnetism in its field coils to start the generation of electricity. A generator that has not been run in a long time will loose this magnetism. Because the field voltage is a DC supply, a battery across the field wiring will energize the coils instantaneously. Doing this several times will cause sparking when the contact to the battery is broken, hence the flash. This intermittent energizing and de-energizing will bring the residual magnetism back into the field coils. When the generator is started, the voltage output should rise to its normal level. If it does the magnetizing of the field coils to bring back the residual magnetism will have worked.
List the factors that affect the voltage building in D.C generator.
DC generator is used to produce direct current. The basic DC generator have four basic parts 1. A magnetic field 2. A single conductor or loop 3. A commutator 4. Brushes
demagnetising effect of dc generator is to reduce main field flux there by reduction in generated voltage.
either a rectifier or a motor generator
There is only 1 type of DC voltage, and that is direct current. In order to better answer your question, you need to be more specific.
NO, generator always generating AC current,when commutator is used,at that time AC is converted in DC.and due to this generator is called dc generator.
A DC generator typically produces a pulsating output voltage rather than a perfectly smooth DC voltage. This is due to the nature of its operation, where the generated voltage fluctuates with the rotation of the armature within the magnetic field. To achieve a smoother DC output, additional components such as filters or voltage regulators are often used to reduce the ripple and stabilize the voltage.
If there is no residual magnetism in the field poles then there would be no flux too induce the initial voltage for self exitation