Answer / vidhya

400Hz was very common in aircraft especially during WWII
and later. It was done because transformers, motors and so
on are very much lighter than with lower frequencies like
60Hz.DC could not be easily be transformed with the
echnology then.However, modern electronics allows DC to be
converted (transformed) with
very small magnetics operating at 100kHz or higher. This
stuff trumps 400Hz. What do they do in modern aircraft?
I was basically referring to the power transmission and
distribution. DC is more efficient and uses less material,
insulation, with less loss than does poly phase AC. That's
why ultra high power transmission lines like the
pacific inter-tie are often DC these days.

Answer / varun

I think(not sure)that, a.c. systems are used only where
long transmission of power is involved.Because,
(remember)d.c. system always has supirior
characteristics,either performance of m/c's or transmission
lines(HVDC).In aircrafts there is no question of long
transmission and also they must maximise their reliability
and efficiency of the operation, hence d.c. m/c's and d.c.
transmission is preferred.

Answer / atique

dont know.

what is the use of earthing ?

8 Answers   Electrical Tech,

---

Explain what is electric traction? Explain few advantages of electric traction system?

0 Answers  

---

Is there any guideline say about display of earthing value near to earth pit

0 Answers  

---

why does connected a indutor with mnsformeretering core of current transformer ?

0 Answers  

---

In winter we seem lightly an electric shock when we touch to doors(sometime)

13 Answers   Infosys, REL,

---

What is the Ohms low calculation

2 Answers  

---

In a transformer, the hysteresis and eddy current losses depend upon 1.load current 2.maximum flux density in core 3.type of lamination 4.supply frequency The correct statements are (a) 1 and 3 (b) 2 and 3 (c) 1 and 4 (d) 2 and 4

9 Answers  

---

how the inductor will work on dc supply?whether it will work or not?

11 Answers   NTPC,

---

Could you measure voltage in series?

0 Answers  

---

why there is spacing between two rails in railway?

3 Answers   DS Group, RRB,

---

why needtwo winding LV and HV in transformer?

1 Answers   Organic Industries,

---

what is the diffrence between mcb &elcb?

2 Answers   Kahramaa, Synergy,

---