1 Answer

Answer :

Series motor has the poorest speed control.

Related questions

Description : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque  (1) Decreases (2) Increases (3) Remains constant (4) None of the above

Last Answer : The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases 

Last Answer : Speed control of a universal motor is achieved by varying field flux with tapped field windings, connecting rheostat in series, applying variable voltage by means of silicon controlled rectifier, applying variable voltage by means of variable auto-transformer.

Last Answer : The speed control of universal motor used for sewing machines is by varying the resistance.

Description : What are the speed control methods of dc motor?

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

Description : speed control methods of three phase induction motor?

Last Answer : Speed control of three phase induction motor

Description : Speed control of the motor using TRIAC

Last Answer : Speed control of the motor using TRIAC:  This basic phase triggering circuit uses the triac in series with the motor across an AC sinusoidal supply. The variable resistor, VR1 is used ... meaning that it may not trigger at the exact same point for each positive and negative half cycle.

Last Answer : Usually wide and sensitive speed control is desired in case of colliery winders.

Last Answer : Speed control by Ward Leonard method gives uniform speed variation in both directions.

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

Description : Armature control of DC motor

Last Answer : Armature control of DC motor

Description : Field control of DC motor

Last Answer : Field control of DC motor

Description : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be

Last Answer : A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be 474 V

Description : The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min (A) 100 rpm (B) 200 rpm (C) 400 rpm (D) 800 rpm

Last Answer : The speed of a 2-pole, 3-phase stepper motor operated by 1200 pulses/min 200 rpm

Last Answer : In variable speed motor a weaker commutating field is needed at low speed than at high speed.

Description : The speed of a D.C. motor can be controlled by varying  1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above

Last Answer : The speed of a D.C. motor can be controlled by varying  1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above

Last Answer : The speed of a D.C. shunt motor can be increased by increasing the resistance in field circuit.

Last Answer : As the load is increased the speed of D.C. shunt motor will reduce slightly.

Last Answer : For the same H.P. rating and full load speed, following motor has poor starting torque differentially compounded.

Last Answer : The speed of a D.C. series motor is inversely proportional to the armature current.

Last Answer : In a D.C. shunt motor, speed is independent of armature current.

Last Answer : The speed of a universal motor is usually reduced by using gearing.

Last Answer : In case of a reluctance motor, when the load is increased so that it cannot maintain synchronous speed the motor will run as induction motor.

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

Last Answer : The speed/load characteristics of a universal motor is same as that of D.C. series motor.

Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.

Last Answer : If the centrifugal switch does not open at 70 to 80 percent of synchronous speed of motor, it would result in damage to the starting winding.

Last Answer : In Ward-Leonard control the lower limit of speed is imposed by residual magnetism of the generator.

Last Answer : For constant torque drive armature voltage control speed control method is preferred.

Description : MCQ on Motor Control Center

Last Answer : 1. MCC stands for ______ a. Motor Control Center b. Motor Control Cost c. Machine Components Center d. None of the above Answer : a. Motor Control Center 2. MCC contains _____ a. Fuse b. MCB c. ... a) Start the motor b) Accelerate the motor c) Decelerate the motor d) Stop the motor Answer : a

Description : Why does the speed of a DC shunt motor decrease as the load increases?

Last Answer : Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.

Description : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ (A) directly proportional to α and Φ (B) ... proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α

Last Answer : The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ directly proportional to α and inversely proportional to Φ

Last Answer : If the speed of a D.C. shunt motor is increased, the back e.m.f. of the motor will increase.

Last Answer : The speed of a universal motor is generally reduced by using gear trains.

Last Answer : The operating speed of a synchronous motor can be changed to new fixed value by changing frequency.

Description : If we change the excitation of synchronous machine will it affect on motor speed?

Last Answer : No, If we change the excitation of synchronous machine it will not affect on motor speed.

Description : An electric motor in which both stator field and rotor rotates with same speed is called?

Last Answer : An electric motor in which both stator field and rotor rotates with same speed is called synchronous motor.

Description : Synchronous motor always runs at which speed?

Last Answer : Synchronous motor always runs at synchronous speed.

Description : The synchronous speed of an 8 pole induction motor supplied power from a 50 Hz source will be ?

Last Answer : Ns         equals        f/pair pole 50/4      - 12.5

Description : A 3-phase, 4-pole, 50Hz induction motor runs at a speed of 1440 rpm. The rotating field produced by the rotor rotates at a speed of ________ rpm with respect to stator field. (A) 1500 (B) 0 (C) 1440 (D) 60

Last Answer : 0

Description : In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is (A) 0.2 Ω (B) 0.3 Ω (C) 0.4 Ω (D) 0.5 Ω

Last Answer : In a 3-phase slip-ring induction motor, the slip at some speed is 0.05. The speed is reduced by inserting an external resistance in the rotor circuit and the slip is 0.15. If the rotor winding resistance per phase is 0.2 Ω, the external resistance is 0.3 Ω

Last Answer : In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will remain unchanged.

Last Answer : The speed of a D.C. shunt motor more than its full-load speed can be obtained by decreasing the field current.

Description : The fall in speed of a dc generator due to increase in load can be corrected by  (1) cooling the armature.. (2) increasing the excitation. (3) reducing the load voltage. (4) increasing the input to the prime mover

Last Answer : It   can  be  corrected  by  increasing  the  input  to  the  prime  mover.

Last Answer : In case of D.C. shunt motors the speed is dependent on back e.m.f. only because flux is practically constant in D:C. shunt motors.

Last Answer : When two D.C. series motors are connected in parallel, the resultant speed is normal speed.

Description : Split phase induction motor

Last Answer : Split phase induction motor : There are two windings used in split phase induction motor. It is a type of single-phase induction motor. There are two winding one is called main winding and ... motor have low starting torque it is used for small fans, blowers, centrifugal pumps, grinders etc.

Description : Describe the reason of using dc series motor for electric trains.

Last Answer : Electric trains require an inverse torque speed characteristics for proper operation. That is a higher torque is required at start (when speed is nil or low) and as the train picks up ... torque - speed characteristics of DC series motors match, these motors are suitable for electric trains

Description : Damper winding in a synchronous motor

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

Description : In a double squirrel cage induction motor, good starting torque is produced as (A) Large current flows through the outer high resistance winding. (B) Large current flows through the inner high ... the outer high resistance winding. (D) Large current flows through the inner low resistance winding.

Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.

Description : A change of 4% in the supply voltage to an induction motor will produce a change of approximately

Last Answer : A change of 4% in the supply voltage to an induction motor will produce a change of approximately 8% in the rotor torque