In D.C. shunt motors as load is reduced?

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

Related questions

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.

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

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

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

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

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

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.

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

Description : In case of conductively compensated D.C. series motors, the compensating winding is provided?

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

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

Answer : Starters are used with D.C. motors because to restrict armature current as there is no back e.m.f. while starting.

Answer : Differentially compound D.C. motors can find applications requiring low starting torque.

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.

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

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

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

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

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

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

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

Description : Slot harmonics are reduced in induction motors by using (A) fractional-pitch windings (B) fractional-slot windings (C) integral-slot windings (D) distributed windings

Answer : Slot harmonics are reduced in induction motors by using fractional-slot windings

Answer : During rheostat braking of D.C. series motors motor is run as a generator.

Answer : The D.C. motors preferred for traction applications beacuse the speed is inversely proportional to the torque and the torque is proportional to square of armature current.

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

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

Description : Why are DC motors used in trains and not AC motors ?

Answer : The reason is torque. torque is inversely proportional to speed..i.e when th knowe train comes to rest position to motion.. initial speed is zero..so it requires high starting torque for ... current will flow through field and armature coils then maximum torque is available at the intial condition.

Description : Which of the following motors can run on both AC and DC? A) Universal motor B) Dual wattage motor C) Flexible motor D) All the above

Answer : Which of the following motors can run on both AC and DC? A) Universal motor B) Dual wattage motor C) Flexible motor D) All the above

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

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%; }

Description : State any four applications of DC shunt motor.

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

Description : Generally, Crawling in squirrel cage induction motors is tendency to run stably at speeds as low as (A) One-third of their synchronous speed (B) One-fifth of their synchronous speed (C) One-seventh of their synchronous speed (D) One-ninth of their synchronous speed

Answer : Generally, Crawling in squirrel cage induction motors is tendency to run stably at speeds as low as One-seventh of their synchronous speed

Answer : As hysteresis motors are free from mechanical and magnetic vibrations therefore these are considered as suitable for sound equipment.

Answer : In a level compounded D.C. generator, full load terminal voltage is equal to no-load terminal voltage.

Description : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is

Answer : A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is 150/√3

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

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.

Description : Damper winding is provided in 3 phase synchronous motors to :

Answer : Damper winding is provided in 3 phase synchronous motors to : provide starting torque and prevent hunting

Description : Stepper motors are used in  (1) printers (2) lifts (3) amplifiers (4) oscillators

Answer : Stepper motors are used in printers

Description : Which of the following motors is being extensively used in servo applications ? A. AC motor B. Field controlled dc motor C. Armature controlled dc motor D. None of these

Answer : Which of the following motors is being extensively used in servo applications ? A. AC motor B. Field controlled dc motor C. Armature controlled dc motor D. None of these

Answer : The capacitors used in single-phase capacitor motors have no polarity marking.

Description : What are the five types of single phase motors used in the industry?

Description : Which of the following test is usually conducted to determine the efficiency of traction motors ? (A) Field’s test (B) Swinburne’s test (C) Hopkinson’s test (D) Retardation test.

Answer : Which of the following test is usually conducted to determine the efficiency of traction motors ? (A) Field’s test (B) Swinburne’s test (C) Hopkinson’s test (D) Retardation test.

Answer : A direct online starter is used for starting motors up to 5 H.P.

Answer : Most of the fractional horsepower motors have either plain or sleeve bearings.

Description : What is the difference between synchronous and asynchronous motors?

Answer : The motor which rotates at constant speed is called synchronous motor. And that constant speed is called as synchronous speed.  And the motor which does not rotates at constant speed are called asynchronous motor. Asynchronous motor is also called as Induction motor.

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.

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

Description : State factors for selection of motors as drive.

Answer : Following Factors governing / or are considered while selecting electric drive (Motor) for particular application: Factors to be considered for selection of Electrical Drives: 1) Nature of Supply:- ... level, load equalization 7) Cost: - Capital, Running and maintenance cost should be less.

Answer : A cumulatively compounded long shunt generator when operating as a motor would be differentially compounded long shunt.

Description : A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly?

Answer : A shunt generator running at 1000 r.p.m. has generated e.m.f. as 200 V. If the speed increases to 1200 r.p.m., the generated e.m.f. will be nearly 240 V.

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.

← Prev Question Next Question →