Ask or Answer

🏠 Home🏷️ Tags❔ Ask a Question✔️ Answer a QuestionUsers
91 views

Please log in or register to answer this question.

1 Answer

Answer :

Dynamic or rheostatic braking,plugging and regenerative braking

Like 0 like

Related Questions

161 views

Last Answer : Dc machine is classified as   self excited  separately excited  permanent magnet  Self excited Dc motor is further classified as  series ... are classified as  long shunt short shunt

1 answer
0 views

Description : Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.

Last Answer : Ans: B Because reversal of Ia would also mean reversal of field and hence of Eb

1 answer
137 views

Description : A DC chopper is used for regenerative braking of a separately excited DC motor. The DC supply voltage is 400V. The armature current during regenerative braking is kept constant at 300 A with negligible ripple. For a duty cycle of 60% ... to the DC supply is  (a) 78 kW (b) 58 kW (c) 38 kW (d) 48 kW

Last Answer : A DC chopper is used for regenerative braking of a separately excited DC motor. The DC supply voltage is 400V. The armature current during regenerative braking is kept constant at 300 A with negligible ripple. For a duty cycle of 60% the power return to the DC supply is  48 kW

1 answer
174 views

Description : Which loss has least proportion in DC machines?  (A) Armature copper loss (B) Field copper loss (C) Magnetic loss (D) Mechanical loss 

0 answers
123 views

Description : Fractional pitch windings are used in DC machines to (A) Reduce copper losses (B) Improve cooling (C) Increase the generated emf (D) Reduce sparking

Last Answer : Fractional pitch windings are used in DC machines to Reduce sparking

1 answer
233 views

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Last Answer : 3  Commutation

2 answers
179 views

Description : The introduction of interpoles in between the main poles improves the performance of DC machines because: (A) the interpole produces additional flux to augment the torque developed (B) the flux waveform ... of the armature is removed (D) a counter emf is induced in the coil undergoing commutation

Last Answer : The introduction of interpoles in between the main poles improves the performance of DC machines because: a counter emf is induced in the coil undergoing commutation

1 answer
224 views

Description :  Three different points are shown on a dc load line. The upper point represents the : -  a) minimum current gain b) quiescent point c) saturation point d) cutoff point

Last Answer :  Three different points are shown on a dc load line. The upper point represents the : -  saturation point

1 answer
144 views

Description : what is the difference between AC and DC current ?

Last Answer : AC is generated using Alternator. DC is generated using DC generator. AC changes its direction periodically. DC do not change its direction periodically. AC have non zero frequency. DC have zero ... Power factor of AC is between 0 and 1. But power factor of DC is always 1.

1 answer
Show MoreAsk QuestionNext Page →