Recent questions tagged commutator

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

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

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

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

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

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

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.