By combining the formula for the reactance of a capacitor with Ohm's Law for a capacitor, I can solve for angular frequency, and divide by 2π to find frequency.
The resulting equation is:
f = I/(2π VC)
Using the given values, I end up with 5.2 kHz, instead of the correct answer of 5.2 MHz. I...
Homework Statement
In the circuit diagram shown , Xc = 100 ohm , XL = 200 ohm , R = 100 ohm , the effective current through the source is ?
Homework Equations
Z= √( R^2 + ( XL - Xc)^2)
Vrms = Irms/ Z
The Attempt at a Solution
I tried to draw the phaser diagram and calculate the relation...
Hi, I have a problem understanding the ac capacitive circuit, where Vc = Vm * sin(ωt), and, current leads the voltage, so at t = 0, v = 0 which means no emf, no pushing energy for the electrons, I think, then how current is max? what is the energy source that supplied the electrons with the...
Hi everyone! This is my first thread :)
I've been working a bit with AC and radio, and would like to make a simple(-ish) circuit in which a 1-volt peak audio signal is stepped up to around 5 volts with a transformer, and is fed into a crystal oscillator to make a crude-but-effective AM...
Hello!
Recently I was going through some old exams and upon encountering this problem (which seemed pretty easy) I got stuck. Exams at my university are composed of individual tasks, each having three subquestions with four plausible answers respectively. Solution sheet gives results only, so...
Homework Statement
the problem is given in the attachment
Homework Equations
basic knowledge of ac circuits and phasor diagrams
The Attempt at a Solution
for point A , i calculated the potential easily. and for point B , i calculated the potential using phasor relationship .. now after doing...
Homework Statement
y = 27
Homework Equations
The Attempt at a Solution
- I calculated the total impedance.
- Divide it with the voltage to get the current.
- Then I use the load impedance to find the voltage load.
- And I calculated the complex power for the load.
I am not comfortable...
Homework Statement
In an undriven RLC-circuit, the characteristic time of the capacitor, ie the time taken for the amplitude of the capacitor voltage ## V_c ## to drop by a factor e, is ## T = 2L/R ##.
We now have a RLC-circuit which is driven by a AC voltage of variable frequency ## \omega ##...
Supposed there is a black box connect to an AC circuit. Inside the black box, there are either a resistor connected with a capacitor or a resistor connected with a inductor. They can be connected either in series or in parallel. The total impedance and phase shift of the black box at 2 different...
Homework Statement
Given the circuit of sinusoidal current (attachment1) with given data:
\underline{Z_3}=200(3-j4)\Omega,\underline{Z_4}=100(3+j20)\Omega,\underline{Z_5}=100(3+j4)\Omega,\underline{Z}=100(2+j5)\Omega,\underline{I_{g2}}=-10(2-j)mA.
After the switch is closed, the increment of...
Homework Statement
Given the circuit of sinusoidal current (attachment 1) with given data:
\underline{Z_3}=200(3-j4)\Omega, \underline{Z_4}=100(3+j20)\Omega, \underline{Z_5}=100(3+j4)\Omega, \underline{Z}=100(2+j5)\Omega, \underline{I_{g2}}=-10(2-j)mA
After the switch is closed, the increment...
Homework Statement
Given the circuit of sinusoidal current (attachment 1) with given data:
\underline{E}=100V,\underline{E_1}=40V,\underline{Z}=(10+j10)\Omega,\omega=10^5rad/s,L=1mH,
C=0.1uF. Find \underline{I_L},\underline{U_{16}}, active and reactive power in the branch 2-5.
2. The...
Hello everyone.
So i live in Lebanon, and since a long time now we have constant power cuts, almost half the day each day. For that the Lebanese made up a system in which each neighborhood has power generators providing electricity to the residents when the power is out. Usually the owners of...
In all tutorials I have read on tesla coils, they have said to use a capacitor spark-gap configuration, to create a tank circuit. I want to know exactly what this means, and what is its purpose. I am not going to build a Tesla coil, I am nearly just interested in the science of it.
Since the resonant frequency of a tank circuit, is completely adjustable, and controlled by the value inductor and capacitor you use, I was wondering if it had any other uses, other than increasing its impedance at its resonant frequency. Can if be used to produce ac signals of its resonant...
Homework Statement
Three receivers, with complex impedance \underline{Z_1}=(125+j375)\Omega,\underline{Z_2}=(700+j100)\Omega,\underline{Z_3}=(500-j500)\Omega, and two sinusoidal current generators of effective values I_{g2}=40mA and unknown I_{g1} are connected. When the switch is open...
Homework Statement
Find the peak value of current through the AC source of the following L-C-R circuit, if peak voltage is ##V_0## and angular frequency is ##\omega_0##.
Homework Equations
I have learnt Vector algebra and calculus (single variable). I was taught how to use phasor diagrams for...
It's pretty easy to find the "working principle" of surface capacitive touchscreen like http://www.elotouch.com/Technologies/SurfaceCapacitive/howitworks.asp [Broken]
Roughly speaking, I know that
A surface capacitive touchscreen has a conductive layer to which some electrodes are attached...
Homework Statement
SOURCE:
v(t) = (311)cos(314t) [v]
IN SERIES WITH:
R = (0.3) [Ω]
L = j(0.7) [Ω]
"load" = 2.5 + j(1.0) [Ω]
Homework Equations
Find the instantaneous current, and the phasor current.
The Attempt at a Solution
(1.) I first found the frequency of the source:
(314) / (2*pi) ≈...
If drift velocity of electrons changes in AC, how does electricity flow through a circuit to then lose potential energy to the devices in the circuit?
Also considering the change in direction, does that mean that the live wire and neutral wire also switch roles in AC mains? I am very confused...
Homework Statement
*(Problems attached as images)*
For first problem:
##\cfrac{|V_2|}{|V_1|} = \cfrac{1}{\sqrt{4+(\omega RC)^2}}##
For second problem:
##\cfrac{|V_2|}{|V_1|} = \cfrac{\sqrt{1+(\omega RC)^2}}{\sqrt{4 + (\omega RC)^2}}##
I have to calculate half power frequency for both...
Homework Statement
How large an inductance should be connected in series with a 120 volt (rms), 60 watt light bulb if it is to operate normally when the combination is connected across a 240 volt, 60 Hz line? (First determine the inductive reactance required. You may neglect the resistance of...
Homework Statement
2. Homework Equations
[/B]
I am trying to prove the equation
$$
\frac{\bar{P}}{V}=\frac{1}{2}E_0^2\sigma_{AC}
$$
which can be rewritten as
$$
\begin{align}
\frac{\bar{P}}{V} &= \frac{1}{2}E_0^2\sigma_{AC}\\
&=\frac{1}{2}E_0^2\ \omega\ \epsilon_0\ \epsilon^{''}_r\\...
Hi. I'm joining this forum to ask about some equipment I need. At the community college where I teach, we do a lab in freshman physics where students measure the input to and output from a transformer. My AC sources are reaching the end of their lives, so I'm looking for replacements. As far...
Homework Statement
Homework Equations
KVL at that loop
The Attempt at a Solution
I can easily solve all the individual current and voltages in this circuit using Mesh analysis and Gaussian Elimination. But how do I get Vx? I can simply add the voltages of the two 10uF capacitors if they are...
Homework Statement
The circuit above has a 29 resistor and a 11.1 mH inductor. Calculate the theoretical phase difference between the current CPA and voltage VPB if the circuit is driven by a sinusoidal voltage source with a peak amplitude of 3.5 V at the following frequencies:
20 Hz
420 Hz...
I have only just found out about inductors, and am trying to figure out how a circuit with an inductor and a capacitor could change dc current to ac current.
With the set up of the circuit, would it suffice just to have the dc supply with a 'gate' that stops/allows through the dc current with a...
Homework Statement
Determine, using the values given in TABLE A, the current I in the circuit of FIGURE 2 by:
(a) mesh analysis
(b) nodal analysis.
Any help verify for part (a)? And to help me get started with (b) as V3 is driving me nuts.
Homework Equations
The Attempt at a Solution
For...
Homework Statement
A voltage source given by ##v_s(t)=25cos(2\pi\times10^3t-30^\circ)## is connected to a series RC load. If R = 1MOhm and C = 200pF, obtain an expression for ##v_c(t)##, the voltage across the capacitor.
Answer known to be: ##v_c(t)=15.57cos(2\pi\times10^3t-81.5^\circ)##...
Hello, this is not a homework question, but is a past year exam question which I'm stumped at. Any help will be appreciated.
1. Homework Statement
We're designing a current reduction system for an AC motor which is modeled as an inductor ##L##in series with a resistor ##R##. This motor is...