In the illustration, the assembly labeled 2 is a ________. EL-0001 A. wound rotor and shaft for a single phase induction motor B. conduction rotor and shaft for a polyphase induction motor C. squirrel cage rotor and shaft for a polyphase motor D. squirrel cage rotor for a single phase induction motor

1 Answer

Answer :

Answer: C

Related questions

Description : In the illustrated device, the part labeled '1A' _________. EL-0001 A. are start and run windings for a single phase shaded pole induction motor B. is the stator for a polyphase induction ... armature for a squirrel cage rotor motor D. are direct current shunt field windings for a universal motor

Last Answer : Answer: B

Description : As shown in the illustration, the purpose of the item labeled 'Z', in assembly No. 2, is to _____________. EL-0001 A. keep the rotor in balance B. align the rotor to the stator C. dynamically balance the rotor D. cool the motor

Last Answer : Answer: D

Description : The purpose of the item labeled 'Z' in assembly No. 2, shown in the illustration is to _____________. EL-0001 A. keep the rotor in balance B. align the rotor to the stator C. dynamically balance the rotor D. cool the motor

Last Answer : Answer: D

Description : Which of the following physical characteristics does a wound-rotor induction motor possess that a squirrel cage motor does not? A. Slip rings B. End rings C. A centrifugal switch D. End plates

Last Answer : Answer: A

Description : A motor using a rheostat in the motor circuit to vary the speed is called a ____________. A. squirrel-cage induction motor B. regenerative braking motor C. wound-rotor induction motor D. synchronous motor

Last Answer : Answer: C

Description : A motor which can conveniently be operated at lagging as well as leading power factors is the (A) squirrel cage induction motor. (B) wound rotor induction motor. (C) synchronous motor. (D) DC shunt motor.

Last Answer : (C) synchronous motor.

Description : The torque and current curves for a three-phase induction motor with a cage rotor, are shown in the illustration. Which of the following statements is true concerning the depicted curves? EL-0056 A. As slip ... D. If the motor is loaded to the point where 40% slip has resulted, it will stall.

Last Answer : Answer: D

Description : A split-phase induction squirrel-cage motor will not come up to speed, even though the rated voltage, rated frequency, and rated load are applied. The suspected trouble could be due to _____________. A. a faulty centrifugal switch B. broken rotor bars C. worn bearings D. all of the above

Last Answer : Answer: D

Description : The speed of a multi-speed, squirrel-cage, induction motor operating in a fixed frequency system can be changed by _____________. A. reconnecting stator windings for different numbers of poles B. ... sequence of the applied voltage D. reconnecting the stator so that no poles have the same polarity

Last Answer : Answer: A

Description : In a three-phase, squirrel-cage type, induction motor the rotating magnetic field is established by the _____________. A. current induced in the rotor windings B. application of a three-phase voltage ... caused by the induced current in the squirrel-cage bars with the magnetic field of the stator

Last Answer : Answer: B

Description : The speed of a three-phase squirrel-cage induction-type motor operating in a fixed frequency system is varied by changing the _____________. A. number of phases to the motor B. number of stator poles C. locked rotor current D. resistance of the rotor winding

Last Answer : Answer: B

Description : A 3-phase, 400 votts, 50 Hz, 100 KW, 4 pole squirrel cage induction motor with a rated slip of 2% will have a rotor speed of (A) 1500 rpm (B) 1470 rpm (C) 1530 rpm (D) 1570 rpm

Last Answer : Ans: B N = NS (1-S) and NS =120 f / p =120 x 50 /4 = 1500 rpm ∴N= 1500 (1-0.02) =1470 rpm

Description : What type of rotor is used in split-phase motors? A. Drum B. Salient pole C. Squirrel-cage D. Wound-rotor

Last Answer : Answer: C

Description : Which of the following types of motors is often designed for use in correcting power factor? A. Polyphase B. Wound-rotor C. Induction D. Synchronous

Last Answer : Answer: D

Description : The speed of a squirrel-cage, multi-speed, induction motor, as used aboard ship, is varied by changing the __________. A. number of connected poles in the stator B. frequency to the motor C. excitation voltage D. resistance of the rotor circuit

Last Answer : Answer: A

Description : The speed of a squirrel-cage induction motor is determined by the ____________. A. diameter of the stator B. number of stator poles C. rotor winding resistance D. rotor conducting bars resistance

Last Answer : Answer: B

Description : Under normal conditions, the speed of a two-speed squirrel cage induction motor is changed by varying the ____________. A. frequency of the applied voltage B. resistance in the rotor circuit C. number of field poles D. amplitude of the applied voltage

Last Answer : Answer: C

Description : The speed of a squirrel cage induction motor is determined by the _____________. A. diameter of the stator B. number of stator poles C. rotor winding resistance D. bar resistance of the conducting rotor

Last Answer : Answer: B

Description : A single-phase induction motor having a relatively high starting torque, is the ___________. A. shaded pole motor B. wound-rotor motor C. capacitor-start motor D. resistance-start motor

Last Answer : Answer: C

Description : A three-phase, squirrel cage, induction motor will run hot due to a/an ______________. A. improper brush position B. reversed commutating pole C. shorted stator D. high power factor

Last Answer : Answer: C

Description : A three-phase, squirrel cage, induction motor will run hot due to _____________. A. open stator coils B. high power factor C. dirty or corroded slip rings D. reversed commutating poles

Last Answer : Answer: A

Description : Which of the following statements is true concerning a polyphase synchronous propulsion motor? A. The motor is started as an induction motor. B. Resistance is gradually added to the rotor circuit. C. ... is held below the rated current. D. The field winding is energized for starting purposes only.

Last Answer : Answer: A

Description : Discoloration of the rotor bars in a squirrel-cage motor is typical evidence of _____________. A. moisture B. overheating C. vibration D. all of the above

Last Answer : Answer: B

Description : Which of the following statements is true concerning the operating characteristics of a squirrel-cage motor? A. Rotor slip is dependent upon the motor load. B. An increase in motor load results in ... results in less generated current. D. A decrease in rotor speed produces a weaker magnetic field.

Last Answer : Answer: A

Description : The variable resistance placed in the rotor circuit of a wound-rotor induction motor provides for __________. A. speed control B. frequency control C. voltage control D. use as a split-phase motor

Last Answer : Answer: A

Description : A single-phase induction motor will only start if you spin the rotor rapidly with the line switch closed. After starting, its speed fluctuates between very slow and half-speed. The problem ... in the ________. A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding

Last Answer : Answer: D

Description : In the illustrated motor, roller bearings are used because __________. EL-0001 A. of their ability to absorb moderate thrust loads B. they electrically insulate the rotor from the frame reducing ... clearance between the rotor and stator is generally as close as mechanical tolerance will permit

Last Answer : Answer: D

Description : In the Squirrel cage induction motors, the rotor slots are usually a slight skew to reduce (A) Windage losses (B) Eddy currents (C) Accumulation of dirt and dust (D) Magnetic hum

Last Answer : Eddy   currents.

Description : A 3-phase delta connected squirrel cage induction motor when started with a DOL starter has a starting torque of 600 NM. Its starting torque when star delta starter is used:

Last Answer : A 3-phase delta connected squirrel cage induction motor when started with a DOL starter has a starting torque of 600 NM. Its starting torque when star delta starter is used: 200 NM

Description : A three-phase squirrel cage induction motor has a starting torque of 150% and a maximum torque of 300% with respect to rated torque at rated voltage and rated frequency. Neglect the stator resistance and rotational losses. The ... maximum torque is  (A) 13.48% (B) 16.42% (C) 18.92% (D) 26.79%

Last Answer : A three-phase squirrel cage induction motor has a starting torque of 150% and a maximum torque of 300% with respect to rated torque at rated voltage and rated frequency. Neglect the stator resistance and rotational losses. The value of slip for maximum torque is 26.79%

Description : A 3 phase, 400 volts, 50 Hz, 100 kW, 4 pole squirrel cage induction motor with a rated slip of 2% will have a rotor speed of: (A) 1500 rpm (B) 1470 rpm (C) 1530 rpm (D) 1570 rpm

Last Answer : 1470rpm

Description : Squirrel cage induction motor has a) Zero starting torque b) Very small starting torque c) Medium starting torque d) Very high starting torque

Last Answer : Ans: B

Description : Slip ring induction motor advantages and disadvantages compared to squirrel cage motors?

Last Answer : Advantages: High starting torque with low starting current Smooth acceleration under heavy loads No abnormal heating during starting Good running characteristics after external rotor resistances are cut out ... cage motors The speed regulation is poor when run with resistance in the rotor circuit

Description : Why skewing is done in squirrel cage Induction motor?

Last Answer : i) For more uniform torque ii) Reduction in noise iii) To decrease magnetic locking tendency

Description : What is the working principle of double squirrel cage induction motor?

Last Answer : In double squirrel cage motor outer cage rotor winding is of high resistance and low reactance. Inner cage winding is of high reactance and low resistance. At the time of starting rotor frequency is equal ... torque than outer cage at the time of running and the motor running torque is good enough.

Description : The power factor of a squirrel cage induction motor is (A) low at light load only. (B) low at heavy load only. (C) low at light and heavy load both. (D) low at rated load only.

Last Answer : (A) low at light load only.

Description : In a 15 HP induction-type motor with a cage rotor, the current required at standstill to produce starting torque is approximately ____________. A. half the full load current B. equal to the full load current C. five times the full load current D. ten to twenty times the full load current

Last Answer : Answer: C

Description : The purpose of a cage rotor winding placed on the rotor of a synchronous motor is to _____________. A. provide excitation to the DC field B. start the machine as an induction motor C. contribute extra torque at synchronous speed D. prevent the machine from falling out of step

Last Answer : Answer: B

Description : Can we add extra resistance in series with squirrel cage rotor? State the reason?

Last Answer : We cannot add extra resistance in series with the rotor because all the copper bars of the rotor are short circuited in both the sides by copper end rings to have a closed circuit.

Description : A characteristic of a wound-rotor induction motor, with a high resistance rotor winding, is _____________. A. low starting torque B. high starting torque C. high speed D. low starting voltage

Last Answer : Answer: B

Description : Reversing any two of the three rotor leads on a wound-rotor induction motor will _____________. A. increase motor performance B. decrease motor performance C. reverse the motor rotation D. have no effect on the direction of rotation or motor performance

Last Answer : Answer: D

Description : The speed of a wound-rotor induction motor _____________. A. will be fixed by the number of field poles B. can be varied by a rheostat-type control C. can only be synchronous speed at full load D. can only attain synchronous speed at no load

Last Answer : Answer: B

Last Answer : The squirrel-cage winding of a single-phase motor is placed in the rotor.

Description : A shaded-pole motor is a ____________. A. synchronous motor B. three-phase induction motor C. compound-wound motor D. single-phase induction motor

Last Answer : Answer: D

Description : What operational characteristics do the components labeled as 'S' and 'R' represent in the motor controller diagram shown in the illustration? EL-0080 A. Standard and Reverse directions B. Stop and Restart features C. Subnormal and Regular loading D. Start and Run functions

Last Answer : Answer: D

Description : A single-phase induction motor fails to start. The rotor is spun rapidly with the line switch closed. Having started by this method it is noted that the motor fluctuates between a very slow ... lies in the ______ A. starting winding B. centrifugal mechanism C. centrifugal switch D. running winding

Last Answer : Answer: D

Description : Compare squirrel cage induction motor and slip ring induction motor any four points.

Last Answer : Comparison Between Squirrel Cage Induction Motor and Slip Ring Induction Motor: Sr. No. Squirrel Cage Induction Motor Slip Ring Induction Motor 1 Rotor is in the form of short circuited bars ... drive e.g. Lathe machine. Used where high starting torque is required e.g. Lifts.

Description : State starters used for i) 3-Ph squirrel cage induction motor (3HP) ii) D.C. motor 

Last Answer : Name the starters used for following motors : i) 3 H.P. 3-Ph squirrel cage I.M: i) DOL starter OR ii) Star-Delta Starter OR ii) Auto transformer starter OR iii) Soft start starter.  ii) D.C Shunt Motor : 1) Armature resistance starter (Three Point Starter) OR 2) Four Point Starter