# 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

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 : 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

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 : 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 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.

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

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

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

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

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

Description : DC shunt motor

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

Last 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 ?

Last 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

Last 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

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

Last 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.

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

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

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

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

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

Last 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

Last Answer : Stepper motors are used in printers

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

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

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.

Last 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.

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

Last 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

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

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

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

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

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

Last 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.

Last Answer : The standard full-load power factor ratings for synchronous motors are unity or 0.8 leading.

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.

Description : State the use of shunt and series resistance used in extension of meter.

Last Answer : Use of shunt and series resistance: i) Use of shunt: To extend the range of Ammeter. ii) Use of series resistance: To extend the range of Voltmeter.

Description : In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

Last Answer : In which of the following transmission lines, the value of the Shunt admittance should be approximated to zero ? (A) A 66 kV 35 km long line (B) A 132 kV 200 km long line (C) A 220 kV 300 km long line (D) A 400 kV 500 km long line

Description : Shunt compensation in an EHV line is used to (A) Improve stability. (B) Improve the voltage profile. (C) Reduce the fault level. (D) Substitute for synchronous phase modifier.

Last Answer : Shunt compensation in an EHV line is used to Improve the voltage profile.

Description : A shunt fault is characterized by (A) Increase in current, frequency and pf (B) Increase in current, reduction in frequency and pf (C) Increase in current and frequency, reduction in pf (D) Decrease in current and frequency