Answer Posted / smita
as compare to dc corona is more in ac and talking about dc
its moer on positive conductor as compre to negative.
| Is This Answer Correct ? | 5 Yes | 1 No |
Post New Answer View All Answers
1. A 380 / 220 V r.m.s. 3-phase 4-wire circuit carries loads of 8 + j8.1 ohm; 4 + j4.1 ohm; and 2 +j2.1 ohmin the three phases respectively. The length of the circuit is 100 m, and the resistivity of the phase conductors is 0.0005 Ω/m. The neutral conductor is of the same size as the phase conductors. a) Select a reference angle 0for the first phase. Then write down the three phase voltages in both polar format and complex number format. b) Make appropriate assumptions, and take temperature effects on resistance is insignificant. Calculate the currents in the three phases. (Note: Determine conductor resistance, and apply Kirchhoff’s Voltage Law) Based on the result, suggest a main switch rating for the circuit. c) Show your preferred direction of neutral current in a diagram, and then determine its value. (Note: Apply superposition principle, and Kirchhoff’s Current Law) Use its magnitude to show that in this circuit, the unbalanced load may increase the voltage drop in some of the phases. (Note: Also observe the common volt drip in neutral) State your assumptions, if there are any. d) Suddenly the neutral wire of the circuit is broken. Estimate the new currents in the first phase, i.e. Phase L1. State your assumptions, if there are any.
state the working of discharge lamp?
what is the difference between earthing and unearth
Is it good to short Neutral and Ground in the PLC or DCS main Power supply. Pls give YES or NO with reasons...? Simarpreet
PLZ sent the previous year question paper for GET in NHPC on my EMail id ppshanker@gmail.com
When can we take Neutral as common neutral link?
DESCRIBE THE CONSTRUCTION ANDOPERATION OF BELT CONVEYORS AND SCR CONVEYORS , DRAW NEAT SKETCHES
what is the difference between surge protection capacitor and surge arrestor
UG cable sizes were specified in sqmm. But practically its not coming to mesure. What's the reason for that? And how they specify the size of the cable?
how does the terminal voltage of transmission lines increase when a capacitor is connected???? This happens not only in transmission lines but also in all circuits. How??? When a capacitor is connected in a transmission line, capacitor also takes energy from the same supply. But how is it able to increase the terminal voltage??? Practically What sequence of events happen during increase in voltage???
why most of junction box vendors providing T5/T6 Temp class jb's for T3 area any special reason?
How can ou verify the size of conductor 50Sq.mm ACSR
A 400 V, 50 Hz, Δ connected synchronous generator has a field reactance of 0.1 Ω and armature resistance of 0.015 Ω. At full load, the machine supplies 1200 A at 0.8 pf lagging. Under full-load conditions, the friction and windage losses are 40 KW and the core losses are 30 KW. What is the machine’s overall efficiency? Ignore any field circuit losses.
How can we calculate the efficiency of a Running (On-Load) Motor ? What parameters are required and what is the method ?
DEFINE BREAKING CAPACITY OF BUSBAR & HOW IT IS CALCULATED?