# The number of brushes in a commutator depends on?

The number of brushes in a commutator depends on amount of current to be collected.

## Related questions

Last Answer : The material for commutator brushes is generally carbon.

Last Answer : In lap winding, the number of brushes is always same as the number of poles.

Last Answer : The rapid wear of brushes takes place due to abrasion from dust, excessive spring pressure, rough commutator bars, high mica insulation between com-mutation bars.

Last Answer : Armature coil is short circuited by brushes when it lies along neutral axis.

Last Answer : Copper brushes in D.C. machine are used where low voltage and high currents are involved.

Last Answer : To avoid formation of grooves in the commutator of a D.C. machine the brushes of opposite polarity should track each other.

Last Answer : The insulating material used between the commutator segments is normally mica.

Last Answer : In a commutator mica is harder than copper.

Description : Number of commutator bars for a 4-pole, 2-layer, DC lap winding with 24 slots and one conductor per layer is (A) 48 (B) 24 (C) 192 (D) 96

Last Answer : Number of commutator bars for a 4-pole, 2-layer, DC lap winding with 24 slots and one conductor per layer is 24

Description : In a DC motor, it is important to place the brushes along ______ A) Magnetic Neutral Axis B) Normal Geometric Axis C) Nominal Geometric Axis D) None of these

Last Answer : In a DC motor, it is important to place the brushes along Magnetic Neutral Axis

Description : Brushes of DC machine are made up of ?

Last Answer : Brushes of DC machine are made up of carbon.

Description : State the function of commutator in DC generator and name the material used for commutator.

Last Answer : Function of Commutator: Commutator converts AC induced in armature winding into DC for external load. Material: i) Commutator segments are made up of Copper. ii) Commutator segments are insulated from each other by Mica.

Description : The function of a brush and commutator arrangement in a dc motor is to  (1) produce unidirectional torque (2) produce unidirectional current in the armature (3) help in changing the direction of rotation of the armature (4) reduce sparking

Last Answer : The function of a brush and commutator arrangement in a dc motor is to produce unidirectional torque

Description : Which of the following does not have a commutator? A) Dynamo B) Induction motor C) Universal motor D) None of these

Last Answer : Which of the following does not have a commutator? A) Dynamo B) Induction motor C) Universal motor D) None of these

Last Answer : Sparking at the commutator of a D.C. motor may result in damage to commutator segments, damage to commutator insulation, increased power consumption.

Last Answer : In a A.C. series motor armature coils are usually connected to commutator through resistance.

Last Answer : In D.C. generators, the brushes on commutator remain in contact with conductors which lie under interpolar region.

Description : What number is your Willpower?

Last Answer : 10 but then I cheated so I don’t know… but I’m being honest about it so 10 or am I lying again… so definitely between 1 and 10

Description : What is the choice of size and number of generator units in interconnected power system?

Last Answer : Choice of Size and Number of Generating Units: 1. The size/rating and number of generating units in such way that they approximately match with the load curve as closely as possible. 2. In ... , if power plant is connected to grid system then generating unit of higher capacity can be installed.

Description :  The number of loop equations required to completely analysing a network comprising of 8 independent branches and 6 nodes including the reference node shall be A) 3 B) 2 C) 4 D) 5

Last Answer :  The number of loop equations required to completely analysing a network comprising of 8 independent branches and 6 nodes including the reference node shall be 3

Description :  A connected graph has ‘5’ number of branches and ‘4’ number of nodes. It's rank is A) 1 B) 2 C) 3 D) 4

Last Answer :  A connected graph has ‘5’ number of branches and ‘4’ number of nodes. It's rank is 3

Description : Then number of T-states of the instruction STA in 8085 microprocessor is A) 10 B) 12 C) 13 D) 16

Last Answer : Then number of T-states of the instruction STA in 8085 microprocessor is 13

Description : The number of terminals present in IGBT is A) 2 B) 3 C) 4 D) 5

Last Answer : The number of terminals present in IGBT is 3

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

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

Description : What is the Gray code word for the binary number 101011?  (1) 101011 (2) 110101 (3) 011111 (4) 111110

Last Answer : What is the Gray code word for the binary number 101011?  (1) 101011 (2) 110101 (3) 011111 (4) 111110

Description : The number of poles of 8/6 stepper motor can be :

Last Answer : The number of poles of 8/6 stepper motor can be : 4

Description : lt the length, number of turns and area of a coil are  doubled, the inductance of the coil

Last Answer : lt the length, number of turns and area of a coil are  doubled, the inductance of the coil is quadrupled

Description : The number of independent equations to solve a network is equal to?

Last Answer : The number of independent equations to solve a network is equal to the number of chords.

Description : The number of electrons in the outer most orbit of carbon atom is?

Last Answer : The number of electrons in the outer most orbit of carbon atom is 4.

Description : A number of forces acting at a point will be in equilibrium if?

Last Answer : The sum of the resolved parts in any two perpendicular directions are both zero

Description : Build using minimum number of CMOS gates. Three input NAND gate. Two input NOR gate Three input NOR gate Two input AND gate Two input OR gate

Last Answer : Three input NAND gate. Two input NOR gate Three input NOR gate Two input AND gate Two input OR gate

Description : What is the maximum number of circuit breakers in a panel?

Last Answer : It depends on that which type of panel is this.

Description : What are the number of valence electrons of atoms in semiconductor?

Last Answer : There are four valence electrons in the atom of a semiconductor.

Last Answer : In case of D.C. machine winding, number of commutator segments is equal to number of armature coils.

Description : Etched or burned bands on the contact faces of the brushes in a direct current generator can be caused by ____________. A. high mica segments B. copper drag on the commutator C. brushes improperly positioned D. copper embedded in the brushes

Description : Which of the diagrams shown in the illustration depicts the proper method of aligning brushes on a commutator? EL-0057 A. A B. B C. C D. D

Description : Brushes in a generator must be positioned in the neutral plane to avoid sparking between the brushes and the _____________. A. yoke B. armature windings C. field pole windings D. commutator

Description : Which of the following is a characteristic of fractional horsepower repulsion start motors? A. They start with a rotating stator field. B. The short circuiting ring is removed from the commutator while ... brushes are removed from the commutator while starting. D. They have a low starting torque.

Description : Sparking at the brushes of a running motor could be an indication of _____________. A. normal operation B. a dirty commutator C. increased brush capacity D. water vapor absorption

Description : Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars? A. A grounded commutator bar B. Using improper carbon brushes C. Aligning the front and rear mica V-rings improperly D. An open circuit in the armature

Description : In the illustrated test, if the lamp fails to light on any of the three windings then _________. EL-0027 A. all three windings are grounded and the motor should be sent out for repair B. ... the motor controller and the controller should be checked D. the test should be redone at a higher voltage

Description : Which of the listed faults cannot be eliminated, EXCEPT by turning or grinding a commutator with a rigidly supported tool? A. Sparking brushes B. Eccentricity C. High mica D. Blackened commutator

Description : Temporary repairs to an open DC propulsion armature coil can be made by _____________. A. connecting the coil ends directly to a pair of negative brushes B. disconnecting coil ends, insulating ... C. grounding the coil ends and short circuiting the commutator bar D. removing the sparking brushes

Description : The function of the commutator in a DC motor is to ________. A. reverse the flow of current through the armature B. reverse the flow of current in the field poles C. reduce the reluctance of the magnetic path through the motor D. shift the neutral running plane of the brushes to prevent sparking

Description : A shunt-wound DC generator is one in which the shunt field windings are in parallel with the _____________. A. commutator B. brushes C. armature D. all of the above

Description : Which of the following components are used to convert alternating current produced in the generator windings to direct current? A. Armature and equalizer B. Commutator and brushes C. Rotor and interpoles D. Field and exciter