Current I
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Current Transformer and Factors
A current transformer is a type of electrical instrument that is produced to provide a flow of current in the secondary circuit which is accurately perpendicular to the current flowing in its primary circuit. To measure current and monitor the operation of the power grid Current transformers are used extensively and is typically defined by its current ratio from primary to secondary.
Current transformers (Current Transformer) are the most commonly used in metering and protective relaying in the electrical power industry where they facilitate the safest requirement of a huge currents, often in the presence of high voltages on the circuit. The current transformer is safely isolates to measure and to control a circuitry from the high voltages basically present on the circuit is beingcalculated. Current transformers are often maintained by passing a single primary turn under a well-insulated toroidal core with many turns of wire wrapped. Current transformers are used for measuring the flow of current and monitoring the operation of the power used. The Current ransformer is basically defined by its current ratio flowing from primary to secondary.
There are some factors improves the current transformer accuracy.They are like burden, rating factor, load, external electromagnetic fields, temperature and physical Current Transformer configuration. Here, the factor of burden is given below.
The amount of impedance is the cause for the burden in a Current transformer circuit. The basic items that are reasons for the burden in the current measurement circuit are switch blocks meters and intermediate conductors and the sources are the conductor between the meter and the Current Transformer. Also, a problem of producing high resistance occurs due to placing a substation meter at some distance from meter which can be overcome by using current transformer with 1 amp which produce low voltage drop.
The Rating factor of a Current Transformer which is dependent on ambient temperature, is a factor used to determine the absolute maximum measurable primary current by multiplying the full load of a Current Transformer.To maintain the accuracy in raising of the ambient temperature, the Current Transformer will have low capacity, and the rating factors of the Current Transformer s will range from 35 degrees Celsius and 55 degrees Celsius.
Another factor for the accuracy ofCurrent Transformer is Physical Current Transformer configuration. If the conductors are not centered in circular or oval, the inaccuracy occurs in Current Transformer and this should be notified for correct accuracy.
Normally, the Current Transformer's are constructed in many ways like passing a single primary turn through a well-insulated toroidal core wrapped with many turns of wire. To measure waveforms of high frequency or pulsed currents within high pulsed power systems wideband current transformers are used specially.
Victor George is an expert in transformer field for the past three years. He wrote many articles about transformers, advantages of transformers and types of transformers. If you want to view more details about the same, just make a look at power transformer. Contact him at victgeorge@gmail.com. Article Source: ArticlesBase.com
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I am getting frustrated with OHMS LAW!!!!?
I know that voltage = current x resistance. I also know that power = voltage x current.
I am trying to figure out how to solve this simple circuit but I cant and its just annoying me!
http://www.flickr.com/photos/67259037@N02/7120005251/
So far I know that the:
Total resistance = 1200 ohms
Total current = 25 milli amps
Total power of the circuit = 750 milli watts (rounded off)
I need to find out the voltage across each resistor (at least I think its each one) and then find the amount current flowing through each one before I can find out how much power each one is using.
If it helps, I know that the answers are:
R1 = 187 milli watts
R2 = 62.5 milli watts
R3 = 277 milli watts
R4 = 222 milli watts
I just dont know how to get these answers and I would like some help. Thanks guys!
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what should I do, dead cat?
So I live near the water and I went out for a smoke letting my dogs out. the neighbors cat was in our back yard. dogs chased it up a poll then it fell in and started to swim way out into the current. I threw it a life jacket and then went out in a kayak, by time i got to it it had drowned, the water is pretty cold. I tried cpr threw its nose but it was gone. Now I feel horrible it happened at 1am, I have the cats body. I guess I gotta wait till morning to give it to my neighbor. Hope he dont flip. What would you do?
the cat was in our gated back yard, where my dogs are always at except at night. Not like they were out roaming. Thanks for all the answers!
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Where should I get a good reference if I'm looking for another job?
Currently I have an active written warning in my personnel file, and it won't disappear until I quit. I was told, by management of all layers, that an immediate resolution is expected but my improvement won't be appreciated due to the permanent written discipline. This means if I continue to work for another 20 years without breaking any rules, doesn't matter how good I become at my job, the active written warning will continue to ruin my career. So I'm considering a graceful, strategic exit.
If I want to find another job before quitting current, I obviously have to state my experiences working for this company on my resume. But how about the reference part? My manager is confirmed not gonna say anything good about me when my new potential employer calls. What should I do with my references? Can I get my coworkers to answer the call?
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Physics E&M questions ***10 points to the first correct answers*** PLEASE HELP!?
The more you answer the better the chance that you'll be chosen, This is from my practice problems as I prepare for my final (you don't have to answer all of them if you can't, but preferably as many as you can and in the shortest amount of time, my exam is tomorrow) THANKS SO MUCH
here they are:
1. A charge +Q is positioned on the x-axis at x=a and another charge +Q is positioned at x=2a. Where along the x-axis should a charge -125Q be positioned to create a net electrostatic force of zero on a test charge at the origin (x=0)?
2. a metal sheet is connected by a conducting wire to ground through a switch that is currently closed. a point charge +Q is brought near the sheet without touching it, and then the switch is opened. After the switch is opened, the charge +Q is removed. What is the charge on the metal sheet before and after the switch is opened? Answer should be in this form: (possitive/negative, positive/negative)
6. A soldier metal sphere of radius R has a total charge +Q evenly distributed on its surface. Assume the electrostatic potential at infinity is zero. What is the potential inside the metal sphere?
8. Two resistors, R1 and R2 are in parallel. Which of the following is true regarding their equivalent resistance?
a) Req is greater than both R1 and R2.
b)Req is less than both.
c)Req is between R1 and R2.
d)cannot tell from the given info
e)Req equals zero.
9.The number of turns per unit length in a solenoid is doubled from its original value by keeping the same number of terms, but making the length of the solenoid half of its original value. Assume the magnetic field is uniform everywhere inside the soilenoid. The new value of the inductance of this solenoid is:
a)reduced to one fourth of its original value.
b)reduced to one half.
c) unchagned
d)increased to twice its origianl value
e)increase to four " " " ".
11.a charged particle moves in a constant magnetic field but not aligned with the field direction (nor aligned against it). Which of the following statements about the magnetic force on the particle is false?
a)force does no work on the particle
b)force chagnes the velocity of the particle
c)tforce only acts on the particle while it is in motion.
e)force changes the kinetic energy of the particle.
14. Two thin straight wire run parllel to each other carrying equal currents in the same direction. if the wires are separated by a distance d and each carry a current I, what is the magnitude of the magnetic field at a point midway between the two wires?
16.in an RLC series circuit, the plate separation of the parallel-plate capacitor is reduced to one-half of its original vale of the frequency of the power source is also reduced to one-half of its original value. What is the new value of the capacitive reactance?
17. The charge on the capacitor plates in an LC circuit performs simple harmoonic oscillations. at an instant when the magnitude of the charge on the capacitor plates reaches a max value, the current through the inductor is what?
19.An RLC circuit is driven at its resonant frequency. The voltage across the inductor:
a)lags the current
b)leads the current
c)is in phase with the current
d)first lags the current and then leads the current
e)first leads the current and then lags the current
20.an RLC circuit consists of a 140 ohms resistor, a 13 microF capacitor and a 390 mH inductor, connected in series with a 120-V, 60 Hz power supply. What is the phase angle between the current and the applied voltage?
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Physics E&M questions ***10 points to the first correct answers*** help is appreciate!?
The more you answer the better the chance that you'll be chosen, This is from my practice problems as I prepare for my final (you don't have to answer all of them if you can't, but preferably as many as you can and in the shortest amount of time, my exam is tomorrow) THANKS SO MUCH
here they are:
1. A charge +Q is positioned on the x-axis at x=a and another charge +Q is positioned at x=2a. Where along the x-axis should a charge -125Q be positioned to create a net electrostatic force of zero on a test charge at the origin (x=0)?
2. a metal sheet is connected by a conducting wire to ground through a switch that is currently closed. a point charge +Q is brought near the sheet without touching it, and then the switch is opened. After the switch is opened, the charge +Q is removed. What is the charge on the metal sheet before and after the switch is opened? Answer should be in this form: (possitive/negative, positive/negative)
6. A soldier metal sphere of radius R has a total charge +Q evenly distributed on its surface. Assume the electrostatic potential at infinity is zero. What is the potential inside the metal sphere?
8. Two resistors, R1 and R2 are in parallel. Which of the following is true regarding their equivalent resistance?
a) Req is greater than both R1 and R2.
b)Req is less than both.
c)Req is between R1 and R2.
d)cannot tell from the given info
e)Req equals zero.
9.The number of turns per unit length in a solenoid is doubled from its original value by keeping the same number of terms, but making the length of the solenoid half of its original value. Assume the magnetic field is uniform everywhere inside the soilenoid. The new value of the inductance of this solenoid is:
a)reduced to one fourth of its original value.
b)reduced to one half.
c) unchagned
d)increased to twice its origianl value
e)increase to four " " " ".
11.a charged particle moves in a constant magnetic field but not aligned with the field direction (nor aligned against it). Which of the following statements about the magnetic force on the particle is false?
a)force does no work on the particle
b)force chagnes the velocity of the particle
c)tforce only acts on the particle while it is in motion.
e)force changes the kinetic energy of the particle.
14. Two thin straight wire run parllel to each other carrying equal currents in the same direction. if the wires are separated by a distance d and each carry a current I, what is the magnitude of the magnetic field at a point midway between the two wires?
16.in an RLC series circuit, the plate separation of the parallel-plate capacitor is reduced to one-half of its original vale of the frequency of the power source is also reduced to one-half of its original value. What is the new value of the capacitive reactance?
17. The charge on the capacitor plates in an LC circuit performs simple harmoonic oscillations. at an instant when the magnitude of the charge on the capacitor plates reaches a max value, the current through the inductor is what?
19.An RLC circuit is driven at its resonant frequency. The voltage across the inductor:
a)lags the current
b)leads the current
c)is in phase with the current
d)first lags the current and then leads the current
e)first leads the current and then lags the current
20.an RLC circuit consists of a 140 ohms resistor, a 13 microF capacitor and a 390 mH inductor, connected in series with a 120-V, 60 Hz power supply. What is the phase angle between the current and the applied voltage?
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Resistor Question!!!!?
Four identical resistors are connected to a battery of voltage V = 10 V as shown in Fig. 26-25. The current I is equal to 0.2 A. What is the value of the resistance R of the resistors? Figure is here (http://www.chegg.com/homework-help/questions-and-answers/four-identical-resistors-are-connected-to-a-battery-of-voltage-v-10-v-as-shown-in-fig-26-2-q2014719)
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whats wrong with my code?
include
#include
#include
int calcNextState(int, int[]);
void PrintState(int []);
int main()
{
int current[20];//current array with size 20
int newarray[20];//newarray with size 20
int i;// counter
int loop=20;
int j;
srand(time(NULL));//the rand function generates random numbers then loops through all the elements
//in the current array and assign them a random number then rand()%2 returns a 1 or 0
for(i=0; i<20; i++){
current[i] = rand()%2;
}
PrintState(current);
for(j=0; j
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