Answer / vigneshwaran

while starting d.c series there is no back e.m.f produced in
it and also it has high torque

Answer / pradyumna chdndra panda

Flux produced in field of DC series motor is less and armature current is slightd reduced at starting time because very low value of resistance is used in dc series stator and by study these relation and effects, we sure that there is no back emf produced in dc series motor that is why ....

Answer / deepak24

dear friend note that in dc series motor, speed is proportional to back emf and inversely proportionally to the field flux now,
Eb=V-IaRa, since Ra is very small so Eb is high.
and since field coil have less no. of turns so fild flux is less

hence by considering above two points speed of series motor is high.

which trsanmission is easy and cost effective AC or DC.

19 Answers  

---

Define open loop control system.

0 Answers  

---

What is the difference in Line PT & Bus PT.

3 Answers   Bhel,

---

WHY EXCITATION OF SYNCHRONOUS MACHINE IS DC NOT AC

8 Answers   NTPC,

---

what is differnt between metering CTs an protection CTs

10 Answers  

---

I NEED THE CABLE SIZE. I=800A AND P=315KW

2 Answers   ABC, Wipro,

---

What are the tests to be done on circuit breaker?

1 Answers  

---

What is electrical energy ,power?

2 Answers   ABB,

---

What is the operating range(tolerance) of voltage and frequency of grid supply in india?

10 Answers   BARC,

---

can we run a motor rated 50Hz,415vac,1440RPM At higher speed then rated on name plate with the help of VFD /drive on long term basis.wheater it will effect the motor life

3 Answers  

---

how much leakage current is allowed in MC61A L&T make relay?

0 Answers   Siemens,

---

Is there any Flood lighting system which produces more light (More power consumption 1000W,400W etc.,), white light and restart immediately after power restoration ?

1 Answers  

---