Q2] Fill in the blank (9 Marks) 1-The current drwan by the armature of D.C. motor is directly proportional to 2- The speed of a D.C. shunt-wound motor will shunt field regulator is increased. 3- The synchronous speed of a three-phase induction motor is number of pairs of poles. Rotor copper losses Rotor input power in induction motor = 5- A 4-pole three-phase induction motor has a synchronous speed of 25 r.p.s. The frequency of the supply to the stator is_ Hz. 6- The power input to a mains transformer is 200VA. If the primary current is 2.5A, the secondary voltage is 2V and assuming no losses in the transformer, the turns ratio step down. is 7- A 200kVA transformer has an iron loss of 1 kW and full load cu loss of 2 kW. Its load kVA corresponding to maximum efficiency is kVA. 8- If cu loss of a transformer at 7/8th full load is 4900 W, then its full-load cu loss would be watt. 4- if the value of resistance of the proportional to the 9- The slight curvature at the lower end of the open circuit characteristic of a self-excited D.C. generator is due to

Q2] Fill in the blank (9 Marks) 1-The current drwan by the armature of D.C. motor is directly proportional to 2- The speed of a D.C. shunt-wound motor will shunt field regulator is increased. 3- The synchronous speed of a three-phase induction motor is number of pairs of poles. Rotor copper losses Rotor input power in induction motor = 5- A 4-pole three-phase induction motor has a synchronous speed of 25 r.p.s. The frequency of the supply to the stator is_ Hz. 6- The power input to a mains transformer is 200VA. If the primary current is 2.5A, the secondary voltage is 2V and assuming no losses in the transformer, the turns ratio step down. is 7- A 200kVA transformer has an iron loss of 1 kW and full load cu loss of 2 kW. Its load kVA corresponding to maximum efficiency is kVA. 8- If cu loss of a transformer at 7/8th full load is 4900 W, then its full-load cu loss would be watt. 4- if the value of resistance of the proportional to the 9- The slight curvature at the lower end of the open circuit characteristic of a self-excited D.C. generator is due to

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter32: Three-phase Motors

Section: Chapter Questions

Problem 6RQ: Name three factors that determine the torque produced by an induction motor.

See similar textbooks

Similar questions

6- Which of the following supply is given to the rotor winding of 3-Phase Induction Motor: a) DC Supply b) AC Supply c) No Supply d) Pulsating Supply 7- 3-Phase Induction Motor will have Starting Torque and Starting Current a) High, High b) Low, Low. c) High, Low d) Low, High 8- Which of the following method is used for controlling the speed of an induction motor: a) Changing number of stator poles b) Supply voltage control c) Frequency control d) All the options are correct 9- Which of the following method cannot be used for starting of 3-Phase Squirrel Induction Motor: a) Star-Delta Starting b) Line resistor startling c) transformer Starter d) Rotor Resistance Starting 10- The rotor of a stepper motor has no: a) windings b) commutator c) brushes d) all of the above
1. The operation of Commutator in DC Motor is * O a) to convert dc to ac O b) to convert ac to dc O c) to convert fixed dc to variable dc O reverse the current direction in the rotating windings each half turn
A freewheeling DC motor is driven with 1000 rpm and a nominal load torque of 80Nm. The field circuit resistance is 200 and the armature circuit resistance is 0.2 O. The field coils are fed with a zero degree transmission angle through a single-phase fully controlled converter connected to a single-phase 240V source. The armature circuit is fed from a single phase 400V source through another fully controlled converter. Magnetic saturation has been neglected, the motor constant is given as 0.8 V - s / A - rad. Assuming that there is no fluctuation in armature and field current, find the control angle of the converter feeding the armature at nominal load. If you want to leave the question blank, click again on the option you marked.
Write a summary ( point) about equivalent cricuit of three phase induction motor .
1- The compole is used to 2- A 4-pole wave winding machine has ------ magnetic circuit. 3- A commutator pitch for the duplex wave winding is equal to - 4- A 2-pole triplex lap winding will have parallel paths. 5- A 6-pole lap wound generator has 900 conductors. The e.mf induced per one turn being 3V. the generated voltage of the grnerator is ( 6-A 10kW, 250 V shunt generator has armature and field resistance of 0.2 and 502 respectively. Then the generated voltage is and
What are the following statements are true for a three-phase induction motor? I. Three-phase induction motor stator winding is fed from a single-phase supply II. Stator carries a three-phase winding III. Rotor carries a short circuited winding a. I,II and III b. I only c. I and II only d. II and III
(6) The air gap power of 440 V, 50 HZ 6 pole 3- phase induction motor is 100 KW. The rotor frequency is 1.3 HZ. Find rotor copper losses per phase.
A 110 V, 60 Hz, 6 – pole single phase induction motor 1/3 hp has the following equivalent circuit impedances: RI = 1.52 ohm, R2 = 3.13 ohm and x1 =2.10 ohm, x2 =1.56 ohm. Xm=58.2 ohm, The Friction, windage and stry losses =16W, the core loss = 35 W, For a slip of 0.05, calculation (a) input current, (b) power factor, (c) developed power, (d) output power, (e) speed (f) in put power (g) air gab power (h) T ind (i) T load 6) efficiency.
Frequency of emf in the stator of a 8 pole induction motor is 50Hz and the rotor emf frequency is 1Hz. The motor speed is ................ Answer
How rotor winding is derived the power in the three-phase induction motor? O a. from Single phase supply O b. from stator winding O c. None of the above O d. from slots
An 8 pole, 50 Hz slip ring induction motor runs at a slip of 2.67% on full load. The rotor resistance per phase of the winding is 0.2 ohm. What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17.33% such that the torque remains same in both the cases. (Ans: 1.1 ohm)
L-1). The 3-phase wound-rotor induction motor has .... . a) high starting torque b) low starting current c) both "a" and "b" d) neither "a" nor "b" L-2). The 3-phase wound-rotor induction.........a) motor has a wire wound rotor b) motor's rotor can be connected to an external resistive load by way of slip rings and brushes c) motor requires more maintenance than the 3-phase squirrel-cage induction motor d) all of the above L-3). The 3-phase wound-rotor induction motor's rotor circuit's resistance should be adjusted so it is__________ during starting. a) low b) high c) either "a" or "b" d) neither "a" nor "b" L-4). Will a 3-phase wound-rotor induction motor start with no external circuit connected to its rotor leads? a) yes b) no