The resistance of armature winding depends on?

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

Related Questions

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
Last 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

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

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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
Last 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

621 views 1 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
Last 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

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

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

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

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Last 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.

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

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

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

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

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Last Answer : Wave winding is composed of that even number which is exact multiple of poles + 2.

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Last Answer : Lap winding is composed of any even number of conductors.

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Last Answer : In D.C. generators, lap winding is used for low voltage, high current.

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Last Answer : In the case of lap winding resultant pitch is difference of front and back pitches.

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

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

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

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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
Last 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

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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
Last Answer : 3  Commutation

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

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

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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
Last 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

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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
Last 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

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

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

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

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

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

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Last 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.

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

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

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

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Why is the armature of DC generator laminated?
Last Answer : The armature of DC generator is laminated to reduce eddy current losses.

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Armature control of DC motor
Last Answer : Armature control of DC motor

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Last Answer : The critical resistance of the D.C. generator is the resistance of field.

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Last Answer : In a D.C. generator, the critical resistance refers to the resistance of field.

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State advantages of short pitch winding over full pitch winding in alternators.
Last Answer : Advantages of Short Pitch Winding over Full Pitch Winding in Alternators: 1) Short pitching reduces the amount of copper needed for end connection when compared with full pitched coil. 2) They ... reduced, thereby increasing the efficiency. 4) The power quality of generated emf is improved.

478 views 1 answer

Damper winding in a synchronous motor
Last Answer : Damper winding in a synchronous motor Serves to start the motor.

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A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts
Last Answer : A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary?  (A) 30 Volts (B) 480 Volts (C) 120 Volts (D) 60 Volts

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A _________ is used to measure the stator % winding temperature of the generator.  (A) Thermocouple (B) Pyrometer (C) Resistance thermometer (D) Thermometer
Last Answer : A Resistance thermometer is used to measure the stator % winding temperature of the generator.

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A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively
Last Answer : A 36 slot, 4 -pole, dc machine has a simplex lap winding with two conductors per slot. The back pitch and front pitch adopted could be respectively 19,17

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Damper winding is provided in 3 phase synchronous motors to :
Last Answer : Damper winding is provided in 3 phase synchronous motors to : provide starting torque and prevent hunting

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Last Answer : In D.C. machines fractional pitch winding is used to reduce the sparking.

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Last Answer : The starting winding of a single-phase motor is placed in stator.

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Last Answer : If starting winding of a single-phase induction motor is left in the circuit, it will draw excessive current and overheat.

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Last Answer : Starting winding of a single phase motor of a refrigerator is disconnected from the circuit by means of a magnetic relay.

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Last Answer : Centrifugal switch disconnects the auxiliary winding of the motor at about 70 to 80 percent of synchronous speed.