# The commutator segments are connected to the armature conductors by means of?

The commutator segments are connected to the armature conductors by means of copper lugs.

## Related questions

Description : The induced e.m.f. in the armature conductors of a d.c. motor is?

Answer : The induced e.m.f. in the armature conductors of a d.c. motor is sinusoidal.

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

Answer : In any rotating machine that part which houses the conductors and in which e.m.f. induced is to be utilised is called armature.

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

Description : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is  (1) 1000V (2) 100V (3) 600V (4) 10,000V

Answer : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is 1000V

Answer : A sinusoidal voltage of 5 Hz is applied to the field of a shunt generator. The armature voltage wave will be of 5 Hz.

Answer : Armature reaction in a generator results in demagnetisation of leading pole tip and magnetisation of trailing pole tip.

Answer : Open circuited armature coil of a D.C. machine is identified by the scarring of the commutator segment to which open circuited coil is connected and indicated by a spark completely around the commutator.

Answer : The armature core of a D.C. generator is usually made of silicon steel.

Answer : The demagnetising component of armature reaction in a D.C. generator reduces generator e.m.f.

Answer : Armature reaction of an unsaturated D.C. machine is crossmagnetising.

Answer : The resistance of armature winding depends on length of conductor, cross-sectional area of the conductor, number of conductors.

Description : The skin effect in conductors is due to non uniform distribution of current in it and major portion of current is near the _______ of conductor.  (1) Surface (2) Center (3) Complete cross section area (4) Axis

Answer : The skin effect in conductors is due to non uniform distribution of current in it and major portion of current is near the Surface of conductor.

Answer : Service mains are the conductors, which connect the consumer's terminals to the distribution.

Answer : Advantage and disadvantages of stranded conductors  Advantages of Stranded Conductors:-  1. Conductor becomes flexible.  2. Its weight reduces.  3. Easy for handling.  4. Easy to ... Stranded Conductors:-  1. Due to stranding of conductor its resistance increases slightly about 2%.

Description : Which have more free electrons: conductors or insulators?

Answer : Conductors have many free electrons whereas insulators have very few or none at all.

Description : Name two good conductors, two good insulators, and two semiconductors.

Answer : In general all metals are good conductors, with silver the best and copper second.

Description : The function of steel wire in ACSR conductors is (A) To take care of surges. (B) To reduce corona. (C) To reduce inductance. (D) To provide additional mechanical strength

Answer : The function of steel wire in ACSR conductors is To provide additional mechanical strength

Description : All good conductors have high?

Answer : All good conductors have high conductance.

Description : Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be?

Answer : Two copper conductors have equal length. The cross-sectional area of one conductor is four times that of the other. If the conductor having smaller cross-sectional area has a resistance of 40 ohms the resistance of other conductor will be 10 ohms.

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

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

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Answer : The armature torque of the D.C. shunt motor is proportional to armature current.

Description : Define armature reaction in an alternator. Explain the effect of armature reaction at various P.F. of loads of alternator.

Answer : Armature Reaction: The effect of armature flux on main flux is called as armature reaction.  Armature Reaction at Various Power Factors: When armature is loaded, the armature flux modifies ... lagging p.f. For capacitive loads the effect of flux is partly distorting and partly strengthening.

Answer : It is the wire wound around a aluminium metal it is found commonly in transformers or motors

Description : A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ohm. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is

Answer : A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ohm. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.87

Description : A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is

Answer : A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is 36 Ohm

Description : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as  (1) synchronous motor (2) synchronous generator (3) asynchronous motor (4) asynchronous generator

Answer : In a synchronous machine, if the field flux axis ahead of the armature field axis in the direction of rotation, the machine is operating as synchronous generator

Description : In a 3 -phase alternator, if there is only magnetizing armature reaction, the load is :  (A) capacitive (B) inductive (C) resistive (D) inductive and resistive

Answer : In a 3 -phase alternator, if there is only magnetizing armature reaction, the load is : capacitive

Description : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole)  (A) has q -axis current only (B) has d -axis current only (C) has both d and q axis currents (D) cannot be divided between q and d axis currents

Answer : The armature current on symmetrical 3 phase short circuit of a synchronous machine (salient pole) has d -axis current only

Description : Aluminium is not used as winding wire for the armature of a dc machine because  (1) aluminium has low resistivity (2) a large winding space is taken by aluminium conductors and creates ... ) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper

Answer : Aluminium is not used as winding wire for the armature of a dc machine because  (2) a large winding space is taken by aluminium conductors and creates jointing problems (3) the thermal conductivity of aluminium is low (4) aluminium has low conductivity as compared to copper

Description : What is the effect of armature reaction? A) Demagnetization of the main field B) Demagnetization of the brushes C) Cross-magnetization of the brushes D) None of these

Answer : What is the effect of armature reaction? A) Demagnetization of the main field B) Demagnetization of the brushes C) Cross-magnetization of the brushes D) None of these

Description : The armature reaction in a synchronous generator supplying leading power factor load is (A) magnetizing (B) demagnetizing (C) demagnetizing and cross-magnetizing (D) magnetizing and cross-magnetizing

Answer : The armature reaction in a synchronous generator supplying leading power factor load is magnetizing and cross-magnetizing

Description : The normal value of the armature resistance of a d.c. motor is?

Answer : The normal value of the armature resistance of a d.c. motor is 0.5.

Answer : When the armature of a D.C. motor rotates, e.m.f. induced is back e.m.f.

Answer : The armature voltage control of D.C. motor provides constant torque drive.

Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.

Answer : In a synchronous motor, the armature current has large values for high and low excitation.

Answer : The armature current of the synchronous motor has large values for low and high excitation.

Description : Why is the armature of DC generator laminated?

Answer : The armature of DC generator is laminated to reduce eddy current losses.

Description : Armature control of DC motor

Answer : Armature control of DC motor

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

Description : For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f. ?

Description :  A 4-pole 460V shunt motor has its armature wave connected with 888 conductors. The   useful flux per pole is 0.02 wb and the resistance of the armature circuit is 0.7Ω. if the  armature current is 40A. Calculate  (i) the speed (ii) the torque

Description : Which of the following are the parts of a DC generator that convert the AC in the armature to DC in the external circuit. Are these parts the: w) field poles x) slip rings and the brushes y) commutator and the brushes z) armature and the core