Answer / k.prakashchandra

You can not have fixed north and south poles in the field
with AC

Answer / raja

When ac supply is provided, the poles will alternate between north and south pole for each half cycle of supply. so there wont be any magnetic interlocking with stator to run at synchronous speed as the polarity changes at the rate of supply frequency. hence for magnetic locking DC supply is used for excitation

Answer / sunit saini

the working principle of syn/mac. is mag. locking which is
not possible in ac

Answer / lokesh

We need a statoinary magnetic flux in synchronous machine,
this flux will be cut by the rotor.

Answer / anil

Yes we can have a ac in rotor.But then we will not call it as a rotor.It will be stationary but this rotor has to be connected to a 3phase supply .Then it will produce a rotating magnetic field which will interact with the stator and create emf.

Answer / ert

BT SUBMIITIN

Answer / shailesh_358

DC excitation provides high starting current required for
excitation

Answer / madhu

to make sym machine self starting

plz tell me Motor IP formula

0 Answers  

what is electricity.

6 Answers   HP, L&T,

Which device is used for the source of emission of electrons in a crt?

0 Answers  

how the earthing point or earthing is taken for ships and airplanes?

1 Answers  

Iam deepthi.i completed my b.tech from electrical engineering.i want to prepare for civil services.i dont have much knowledge about these exams,but i have great zeal of cracking exams.plz provide me suggestions to which options i can select for optionals

7 Answers  

why always out of the 3 phase(RYB) of supply, in Y phase w.r.t the voltage is higher? on R & B phase the voltage will be lower as compared to Y phase?

1 Answers  

How to set the relay,,??

0 Answers   Megatron Solutions, Nestle,

explain why the armature voltage changes when the field rheostat is varied in self excited DC generator

2 Answers  

if 2 coil of 1000W connect in series and 200 v is applied across it . then what is the total power of coil when coil have only resistive load .

0 Answers   BSNL,

What is the difference between CRNO and CRGO in an transformer and what is the advantages of these two.

13 Answers   Anchor, CIL, ETA, Kirloskar,

Wghat is D-curve MCBs

3 Answers   Indeco,

Under wat condition statcom operates as an inductor for the transmission line?

0 Answers