# In a D.C. shunt motor, speed is?

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

## Related questions

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

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.

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.

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 D.C. shunt motor more than its full-load speed can be obtained by decreasing the field current.

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.

Description : 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

Last Answer : For a D.C. shunt motor if the excitation is changed torque will change but power will remain constant.

Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.

Last Answer : In a D.C. shunt motor, under the conditions of maximum power, the current in the armature will be more than full-load current.

Last Answer : If the field of a D.C. shunt motor gets opened while motor is running the motor will attain dangerously high speed.

Description : If field current is decreased in shunt dc motor, the speed of the motor (a) remains same. (b) increases. (c) decreases. (d) none of the above.

Description : DC shunt motor

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Description : State any four applications of DC shunt motor.

Last Answer : Applications of DC shunt motor: 1) Lathe machines 2) drilling machines 3) milling machines 4) Printing machinery 5) Paper industry 6) centrifugal and reciprocating pumps 7) blowers 8)fans

Last Answer : If a D.C. shunt motor is working at full load and if shunt field circuit suddenly opens this will make armature to take heavy current, possibly burning it.

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. series motor is inversely proportional to the armature current.

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

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

Last Answer : The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is 0.5.

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 : In D.C. shunt motors as load is reduced the speed will remain almost constant.

Last Answer : In a manual shunt motor starter over load relay is connected in series and no volt relay in parallel with the load.

Last Answer : In a differentially compounded D.C. motor, if shunt field suddenly opens the motor will first stop and then run in opposite direction as series motor.

Last Answer : If a D.C. shunt motor is working at no load and if shunt field circuit suddenly opens this will result in excessive speed, possibly destroying armature due to excessive centrifugal stresses.

Last Answer : The purpose of retardation test on D.C. shunt machines is to find out stray losses.

Last Answer : D.C. shunt motors are used for driving machine tools.

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

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.

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.

Description : 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.

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

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 : 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

Description : 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.

Last Answer : At the instant of starting when a D.C. motor is put on supply, it behaves like a low resistance circuit.

Description : As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit?

Last Answer : As there is no back e.m.f. at the instant of starting a D.C. motor, in order to prevent a heavy current from flowing though the armature circuit a resistance is connected in series with armature.