# The speed of a D.C. series motor is?

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

## Related Questions

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

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

In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is :
Last Answer : In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is : 0.075

Last Answer : In a D.C. series motor, if the armature current is reduced by 50%, the torque of the motor will be equal to 25% of the previous value.

Last Answer : A D.C. series motor is that which has its field winding consisting of thick wire and less turns.

Last Answer : The direction of rotation of a D.C. series motor can be changed by interchanging field terminals.

Last Answer : A.C. series motor as compared to D.C. series motor has smaller brush width, less number of field turns, more number of armature turns, less air gap.

Last Answer : If a D.C. series motor is operated on A.C. supply, it will spark excessively, have poor efficiency, have poor power factor.

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

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

What are the speed control methods of dc motor?
Last Answer : Field control of DC motor Armature control of DC motor

State the modification to be done in dc series motor to work satisfactorily as ac series motor. State applications of ac series motor.
Last Answer : Modifications are necessary in a dc series motor so that it operates satisfactorily on ac supply. The modifications are as follows:  1) AC series motor is built with a few field turns as ... and grinders 5) High speed vacuum cleaners 6) Sewing machines 7) Food processors 8) Drilling machine

Brake test on DC series motor
Last Answer : .embed-container { position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; } .embed-container iframe, .embed-container object, .embed-container embed { position: absolute; top: 0; left: 0; width: 100%; height: 100%; }

Last Answer : When a D.C. series motor is connected to A.C. supply, the power factor will be low because of high inductance of field and armature circuits.

What are the advantages of DC series motor?

Why dc series motor should not be started at no load?

Why a dc series motor has a high starting torque?

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.

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

In case of conductively compensated D.C. series motors, the compensating winding is provided?
Last Answer : In case of conductively compensated D.C. series motors, the compensating winding is provided in series with armature winding.

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

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.

Last Answer : Series motor has the poorest speed control.

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 universal motor is usually reduced by using gearing.

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

Why the speed of synchronous motor is constant?

speed control methods of three phase induction motor?
Last Answer : Speed control of three phase induction motor

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.

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.

Write two applications of D.C. series motor.
Last Answer : The applications of D.C. series motor: 1. Cranes 2. Hoists 3. Trolley and cars 4. Conveyors 5. For traction work i.e. electric locomotives 6. Elevator 7. Air compressor

Last Answer : In A.C. series motor compensating winding is employed to reduce sparking at the brushes.

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

The function of a brush and commutator arrangement in a dc motor is to  (1) produce unidirectional torque (2) produce unidirectional current in the armature (3) help in changing the direction of rotation of the armature (4) reduce sparking
Last Answer : The function of a brush and commutator arrangement in a dc motor is to produce unidirectional torque

Last Answer : If a D.C. motor designed for 40°C ambient temperature is to be used for 50°C ambient temperature, then the motor is to be derated by a factor recommended by manufacturer and select the next higher H.P. motor.