# In case of D.C. shunt motors the speed is dependent on back e.m.f. only because?

254 views

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.

## Related questions

346 views

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.

161 views

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

71 views

Description : Do AC induction motors have back EMF?

429 views

Last Answer : The armature may burn if the back e.m.f. of a D.C. motor vanishes suddenly.

91 views

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

211 views

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

498 views

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

137 views

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

144 views

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

91 views

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

388 views

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

2.7k views

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.

2.6k views

Description : What is the back EMF of a dc motor?

98 views

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.

155 views

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

124 views

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

358 views

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

170 views

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

220 views

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

383 views

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.

140 views

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

128 views

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

96 views

Description : What is back emf?

Last Answer : Back EMF: When a current carrying conductor is placed in a magnetic field it experiences a force; when it moves due to the force it (conductor) cuts the magnetic field due to which an emf is ... (hence the applied armature voltage) is opposed by the induced emf which is therefore called as Back emf.

70 views

Description : The back emf of synchronous motor depends on?

Last Answer : The back emf of synchronous motor depends on load angle.

78 views

Description : What is back EMF of synchronous motor?

138 views

Description : What is back EMF in inductor?

78 views

Description : What is the back EMF in Transformers?

68 views

Description : What is the back EMF of the motor?

109 views

Description : What is the back EMF?

Last Answer : When the armature of a d.c. motor rotates under the influence of the driving torque, the armature conductors move through the magnetic field and hence e.m.f. is induced in them as in a generator. The ... that energy conversion in a d.c. motor is only possible due to the production of back emf.

2.8k views

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.

384 views

Description : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is  (1) 1000V (2) 100V (3) 600V (4) 10,000V

Last Answer : The induced emf in the armature of a lap -wound four -pole dc machine having 100 armature conductors rotating at 600 rpm and with 1 Wb flux per pole is 1000V

95 views

Description : The counter e.m.f. of a d.c. motor?

Last Answer : The counter e.m.f. of a d.c. motor helps in energy conversion.

211 views

Last Answer : When the armature of a D.C. motor rotates, e.m.f. induced is back e.m.f.

143 views

Description : DC shunt 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%; }

116 views

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

161 views

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.

77 views

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

164 views

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.

193 views

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

89 views

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

163 views

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.

410 views

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.

424 views

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

119 views

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

272 views

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

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

1.8k views

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?

Last Answer : 200V/E2 = 1000/1200 E2= 240 V

101 views

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

71 views

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

Last Answer : Stepper motors are used in printers

82 views

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