Answer / ghanshyam singh

active power is V.I.cos(theta)
while reactive power is V.I.sin(theta)

Answer / v.r. shinde

For active power.

P= V*i*cosQ ( watts) wherw Q is the angle between phase
vol. & phase current.

For Reactive power.

P = V*I. ( VA)

What is use of 3phase instead of single phase?

12 Answers   DCM, L&T,

---

why rotor resistance starter is not suitable for squrielcage induction motor?why it is suitable for slipring induction motor?

5 Answers  

---

How to select a cable size according to load

1 Answers   Red Bull,

---

Any one can explaination about calibration with rotating sub standards?

1 Answers  

---

we have earthmat at 110KV substation.we would like to take earth resistance.b some says that by connecting earth megger terminals (C1,P1) at middile point of earthmat (at riser) will cause voltage gradient at other earthmat nods and dont get exat earth resistance.when connecting at end nods will get exat value . is it correct .please explain

1 Answers   TNEB Tamil Nadu Electricity Board,

---

if a 3phase 100kva distribution transformer , 400 v,50 hz, 4-wire system is loaded at 160 k.w mostly 1-phase Lighting & Airconditioning split a.c load what will be the net effect on the power system in terms of voltage, powerfactor, current , efficiency of xformer

1 Answers  

---

What are formula we can apply to determine the HT/LT current of 11KV/433V transformer except KVA/LV×√3. ?

2 Answers  

---

What are the criteria shall be considers for sizing Fuse and MCB? If the rated current is 10Amps what should be the fuse size / MCB Size?

1 Answers  

---

why frequency should be constant?

2 Answers  

---

which braking is used in traction motor and what is its working send at mukeskumar27@hotmail.com

2 Answers  

---

what is the meaning of number in (11, 31, 61,14, etc. CDG11, CDG31, CDG61, DDT32

1 Answers  

---

15 kva dg set single phase takes 63amp( approximate) while same rating 15kva three phase takes 35amp approximate. why ? and what will be per phase current for 15 kva

2 Answers   TVI,

---