Answer Posted / t eswara rao

During the breaker opening operation an arc will be produced
in between moving contacts and fixed contacts. It require
any medium to produce an arc. If there is no medium, there
is no arc. No medium means it is empty or VACUUM. So this
technique is used for quenching the arc in the vacuum
circuit breakers. So it is very clear that in perfect
vacuum, there is no arc produced.

In Air Circuit Breaker, air is used as arc quenching medium.
it is very simple in construction and cost is also low where
as the Vacuum circuit breaker is very costly due to its its
complicated construction for maintaining the vacuum in the
vacuum chamber

Should power factor be low or high?

1171

---

In aerodynamic turbines which element is NOT there a.stator b.compressor c. Fuel intake system d.fans

2130

---

What is sensitivity of a measurement?

1127

---

draw vector diagram and +ve,zero sequence diagram of symmetrical three phase fault.

2026

---

Define liftable weight of a transformer? Does the total weight of transformer include oil weight?

2486

---

Explain the construction of the conservator, operation and purpose, and draw the diagram of the conservator.

2503

---

Explain Need of a starter in a dc motor.? Also explain any two starting and speed control method of dc motor?

1710

---

what is the mechanical safety of DG ?

2158

---

What will happen if we on 200kvr capacitor bank(11kv in bus)If there is low load on transformer (1.5 mva 33/11 kv)

1561

---

i am studying in final year can i allowed for 23rd UES of Indian army

2116

---

why transformer ratings in kva? & DG ratings in kva? & Motor ratings in kw/HP?

1505

---

Why electrical power generation and transmission done in 3 phase system not more than 3 phase ?

3061

---

concept of busbar and load dispatching..?

2423

---

What would be the size of wire used for 2 Ton of window A.C?

1905

---

how to check three phase motor torque value?

2364

---