In electric and electronic systems, reactance is the opposition of a circuit element to the flow of current due to that element's inductance or capacitance. Greater reactance leads to smaller currents for the same voltage applied. Reactance is similar to electric resistance in this respect, but differs in that reactance does not lead to dissipation of electrical energy as heat. Instead, energy is stored in the reactance, and a quarter-cycle later returned to the circuit, whereas a resistance continuously loses energy.
Reactance is used to compute amplitude and phase changes of sinusoidal alternating current (AC) going through a circuit element. Like resistance, reactance is measured in ohms, with positive values indicating inductive reactance and negative indicating capacitive reactance. It is denoted by the symbol
X
{\displaystyle \scriptstyle {X}}
. An ideal resistor has zero reactance, whereas ideal inductors and capacitors have zero resistance – that is, respond to current only by reactance. As frequency increases, inductive reactance also increases and capacitive reactance decreases.
Hello,
I'm a little new to Smith Charts and have been having difficulty trying answer this particular question below.
Homework Statement
The problem states there is a 12.5 m long, 100 Ω lossless transmission line terminated with a load impedance Zl = 50 + j110 Ω. The line is...
I have just done an experiment on finding the reactance of (a)an air-core inductor and (b)an inductor with a soft-iron core.
I have plotted a graph of Vrms against Irms for each experiment.
For the graph in (a), the straight line can pass through origin; yet, for the graph in (b), the straight...
For inductors, it is the induced e.m.f. which resists the current flow.
However, I don't quite understand how capacitors resist the current flow.
Why is there capacitive reactance?
What does 'A built-up electric field resists the change of voltage on the element' mean?
My notes say reactance is the magnitude of impedance, so I assume it means this:
|Z| = \sqrt{X^2 + Y^2}
but this is contradicted by numerous internet sources I've read which say that it is the magnitude of the complex part of impedance |Y| . Could someone clarify this?
I'm more inclined...
Homework Statement
I am trying to complete a lab about RC circuits. I was told to make a graph of both the high-pass and the low-pass filter (frequency vs. Vin/Vout). Then I was asked this question:
"Explain why the two lines on your graph should always cross at the frequency where XC =...
unknown reactance ...how to solve?
Homework Statement
a circuit with the unknown X (pure reactance) in sereis with a two parallel impedance.Z1= 4-j8 ; Z2= 1+j10 ...and total power factor is 0.707.. find the unknown reactance.
Homework Equations
p.f. = Rtotal/Ztotal...
The Attempt...
Homework Statement
What is the peak current when the voltage is applied across a pure inductance of value 0.1H?
We're told that the Peak Voltage is 340V, that the power supply is rated at 240V rms.
f=50hz
Homework Equations
XL = jwL
w=2pi*f
The Attempt at a Solution...
Homework Statement
consider a circuit expressed by v(t)= 100cos \omega t
and i(t)=2cos(\omega t+\pi / 3) .
Find the reactance.Homework Equations
Z=\frac{V}{I} = R+jXThe Attempt at a Solution
Z=\frac{100}{2\angle \pi /3} = 50\angle -\pi /3 = 46 - j19
Does the negative imaginary part mean...
I'm conducting a seminar at college on application of AC to passive components.
To Demonstrate what inductive reactance is , i want to wind a coil , connect it to a DC source , find the resistance. Then i want to directly connect it the AC mains and find th effective resistance again and show...
Not sure how to properly use the youtube tags.
https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=ZR-H7CxhEZc
https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=2iWPff2jEo0
https://www.youtube.com/watch?v=http://www.youtube.com/watch?v=TMfJGwngUAY...
Has anyone come across, or may be able to point me in the direction of a method for evaluating the inductive reactance of a circular loop when the wavelength of the applied signal is significantly less than the conductor length of the loop - and more particularly when;
A. The driven...
Has anyone come across, or may be able to point me in the direction of a method for evaluating the inductive reactance of a circular loop when the wavelength of the applied signal is significantly less than the conductor length of the loop - and more particularly when;
A. The driven wavelength...
Homework Statement
the power factor of a load is 0.866 lagging.the voltage is 200v and the current is 5A.caculate the equivalent series reactance and resistance of the load.
Homework Equations
cos.theta = power factor = resistance / impedence= 0.866
volt = ampere / impendence
The...
Homework Statement
What is the reactance of a 0.1-H inductor if the frequency is 60 Hz?
Homework Equations
z=jwL
where z is impedance, j is imaginary unit, L is inductance
x=wL=2pifL
Z=R+jX
The Attempt at a Solution
I know this is pretty basic, but I'm not sure which equation to...
Homework Statement
A solenoid with a radius of 8.0 10-3 m and 170 turns/cm is used as an inductor in a circuit. When the solenoid is connected to a source of 15 V rms at 22 kHz, an rms current of 3.7 10-2 A is measured. Assume the resistance of the solenoid is negligible.
(a) What is the...
I have a quick question about a problem requiring calculating impedance of a circuit where there is no capacitor. The formula for impedance Z is
Z=sqrt(R^2 + (Xl - Xc)^2).
I am told capacitive reactance Xc = 0 because C = 0 (there is no capacitor in the circuit). But the formula for Xc is Xc...
Hello all!
I am a student of electrical & electronic engineering, in my final year; for my dissertation, I am exploring the possibility of scavenging energy from a magnetic field in order to power a wireless sensor..I am using a coil of rectangular cross section with a magnetic core occupying...
How do we derive the opposition to current flow (AC signal) due to capacitance without using complex numbers?
Is the capacitor's reactance a constant or an average?
If I were to measure the instantaneous voltage across a capacitor and the instantaneous current through it, shouldn't I get...
a. The reactance of an inductor is 100 ohms at 2kHz. What is the inductance of this inductor??
b. At what frequency is the reactance of a 3.5-mH inductor equal to 10 ohm?
I am not even sure what equations to use for these two questions. I know that for a the inductive reactance equation...
Homework Statement
Hi
I hope I write in the right thread, if not, my apologies to the moderator. I am not a physisist, but I am very interested in physics and I am doing medical physics right now, and wondered if you guys could help me with something (probably easy for you, but I don't seem...
In the case of an open-circuit test of transformer, when I increase the supply voltage, i realize the magnetising reactance (Xm) decreases, why does this happen?
Now if we take the impedence for a circuit. Xc for the capacitive component and Xl for the inductive component and equate them, that is we equate the impedance then we can get the same impedance from both a capacitive as well as a inductive load, we get something like this.
Now, in...
Say we have an inductor connected to an AC voltage source. Current will then lag voltage by 90 degrees.
Does the current maintain it's previous value (as if the inductor was not there) but 90 degrees out of phase, or is it still dependent only on voltage?
Rephrasing (in case that was poorly...
1. I am currently progressing through my assignment, however I have been given a circuit with 2 values of Z:
Z1 has a magnitude of 30 and angle of -31.
Z2 has a real value of -12 and an imaginary number of -36.
2. When these are both converted to complex number format:
Z1 = 25.715 -...
Could someone please help me out with this question, I can't find it everywhere in my book. Its a question I need to know for my exams as well.
Q. Distinguish between reactance, resistance and impedance and illustrate their relationship on an impedance phasor diagram.
1.
A RLC circuit is used in a radio to tune into an FM broadcasting station at 99.7 Mhz. The resistance in the circuit is 12.0 ohm, and the inductance is 1.40 uH (micro Henry) what capacitance should be used?
this question is tricky what i tried to do is used XC=1/wC where C is capacitance...
:cry: hi i got 2 questions here fairly confusing was wondering if i can get some help thanks
1. consider a series RLC circuit in which R is an incandescent Lamp C is some fixed capacitor and L is a variable inductance. The source is 240 V ac.
explain why the lamp glows brightly for some...
i seemto be frequenting this board more than i intended to but i physics is not my strong point at all so if i seem bothersome apologize about that and i also try to put what i have done sor for in the problem so it don;t seem like i am not trying so here goes and besides does anyone know where...