19.a. The magnets that are used in the field of a quality DC PM motor are made from A. rare-earth material. B. special aluminum-nickel compounds. C. natural magnets. D. magnetized steel. End of exam 19.b. A DC motor that has interpoles will have the interpole windings in A. parallel with the armature. B. series with the field windings. C. series with the armature. D. parallel with the field windings.

19.a. The magnets that are used in the field of a quality DC PM motor are made from A. rare-earth material. B. special aluminum-nickel compounds. C. natural magnets. D. magnetized steel. End of exam 19.b. A DC motor that has interpoles will have the interpole windings in A. parallel with the armature. B. series with the field windings. C. series with the armature. D. parallel with the field windings.

Electric Motor Control

10th Edition

ISBN:9781133702818

Author:Herman

Publisher:Herman

Chapter43: About Dc Motors

Section: Chapter Questions

Problem 1SQ

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Similar questions

1. It is the constant speed at which motor generates the electromotive force? 2. It means the poles of the rotor projected towards the armature winding? 3. It is the process of inducing the magnetic field on the parts of the motor with the help of an electric current? 4. The magnitude of stator back EMF of synchronous motor depend on, what? 5. It is placed on the brushes which are mounted on shaft of the synchronous motor?
(TRUE OR FALSE) - Shunt motor should not be started on no-load. - Field copper loss is likely to have highest proportion at rated load ofthe DC generator. - In a DC generator, the iron losses mainly take place in the commutator. - Energy conversion of DC generator is based on the principle ofproduction of dynamically terminal voltage. - Increasing the speed of DC motor, the back emf will decrease but theline current falls. - The current drawn by the armature of DC motor is directly proportionalto torque. - Lenz’s law rule is used to determine the direction of rotation of dcmachines. - Compound dc motor at no-load it regulates highest speed. - The direction of this force is perpendicular to both the wire and themagnetic field in DC motor. - The direction of DC motor induced emf is such that the same of thearmature current.
Q5. Explain Speed control methods of wound induction motor with the help of diagram? Q6. Briefly explain the construction of DC machines with help of diagram?
Q/ When a series dc motor is operated without a load, which of the following conditions occurs? * Ans 1- The armature draws excessive current 2- The armature speeds out of control 3- The armature will not turn 4-The voltage requirement increases
Which of the characteristics given in the figure below is the efficiency-output of a DC shunt motor show the relationship between strength? Get your answer on the equivalent circuit of the engine Explain using the mathematical equivalence ? = ? (??)
A 3-phase, 60 Hz, six pole, 220-volt wound rotor induction motor has a stator that is connected in Delta and the rotor that is connected in Wye. The rotor has haft as many turns as that stator. the RR is equal to 0.1- ohm and XBR is equal to 0.5-ohm (a) calculate also the starting torque developed by the motor (b) For over all operation of this induction motor, calculate the efficiency based on the gathered data.
A 100kW, 230V, shunt generator has an armature resistance and field resistance of 0.05Ω and 57.5Ω. If the generator operates at rated voltage. SPL is 1.8kW, a) At what load does the generator achieve maximum efficiency? b) What is the value of this maximum efficiency?
3. HOW THE BACK EMF OR COUNTER EMF IS PRODUCED? 4. DIFFERENTIATE THE TYPES OF DC MOTOR THROUGH: a. SCHEMATIC DIAGRAM/CIRCUIT DIAGRAM b. VOLTAGE EQUATION c. CHARACTERISTIC IN ACCORDANCE OF SPEED VS ARMATURE CURRENT AND SPEED VS TORQUE DEVELOP?
17. A single-phase, 120 V, 60 Hz, four-pole, split-phase induction motor gave the following blockedrotor test data:VIP Main winding 32 4 80Auxiliary winding 40 4 128a) Determine the standstill impedances of the main and auxiliary windings.b) Determine the values of the resistances to be added in series with the auxiliary winding to obtain maximum starting torque.c) Compare the starting torques and starting currents with and without the added resistance in the auxiliary winding circuit if the motor is connected to a 120 V, 60 Hz supply
21.a. When field voltage is controlled to provide a method of variable speed control, the system is using aconcept known as fieldA. stability.B. drive.C. bias.D. weakening. 21.b. What type of motor has the same wire diameter in both the field and the armature coils?A. Interpole-woundB. Series-woundC. Compound-woundD. Shunt-wound
The nameplate rating of a shunt motor is 150hp,600 volts, 205A, and 1700 rpm. The resistance of the shunt field circuit is 240 ohms, and the total armature circuit resistance is 0.15 ohm. The motor has a commutating winding, and armature reaction is neglected. Calculate the full-load efficiency of the motor.
11. Armature copper loss of DC motor is constant with the load. Select one: True False