What is Rc circuit: Definition and 394 Discussions
A resistor–capacitor circuit (RC circuit), or RC filter or RC network, is an electric circuit composed of resistors and capacitors. It may be driven by a voltage or current source and these will produce different responses. A first order RC circuit is composed of one resistor and one capacitor and is the simplest type of RC circuit.
RC circuits can be used to filter a signal by blocking certain frequencies and passing others. The two most common RC filters are the high-pass filters and low-pass filters; band-pass filters and band-stop filters usually require RLC filters, though crude ones can be made with RC filters.
Homework Statement
A 2.00μF capacitor with an initial charge of 5.10μC is discharged through a 1.3 kΩ resistor.
a) calculate the current through the resistor 9.00ms after the resistor is connected across the capacitor
b) what charge remains on the capacitor after 8.00ms
c) what is...
Homework Statement
http://img193.imageshack.us/img193/3696/aasdff.th.png
Uploaded with ImageShack.us
The Attempt at a Solution
(a) No current, so no time constant since C = 0 for it stores no charge
(b) Current immediately is driven through so \tau = (R_{1}+R_{2})C
(c) I pulled the...
Homework Statement
The Attempt at a Solution
As at t=0 the capacitor behaves as a wire ... so the circuit at t=0 will be like:
q at any time for this circuit will be,
q \ = \ CE(1-e^{-t/\tau}) + Q_oe^{-t/\tau}
differentiating it will give current,
i \ = \ \frac{Ee^{-t/\tau}}{R} \ - \...
Homework Statement
A 2.9 MΩ and a 2.8 μF capacitor are connected in series with an ideal battery with an EMF of 3 V. At 2 seconds after the circuit is initially connected to the battery:
What is the rate at which energy is being stored on the capacitor?
Homework Equations
dq/dt = v/r *...
Homework Statement
What is the current through R2 immediately after the switch S is closed?
C = 7.95x10^(-6) F , R1 = 27.5 Ohm , R2 = 10.5 Ohm , and Vo = 20.0 V
Homework Equations
I don't know what to use?
The Attempt at a Solution
I thought maybe I use two loops, the left and...
Homework Statement
At t=0m the switch is open and both capacitors are uncharged. What are the charges on each plate (magnitude and sign) of each capacitor long after the switch is closed and capacitors are fully charged?
Homework Equations
q=C E(1-e^(-t/RC)
The Attempt at a Solution...
Homework Statement
Two capacitors (c1 = 11 and c2 = 15 μF) are charged in series by a 11 V battery. Find the time constant of the charging circuit. (r = 4 Ω).
Homework Equations
V=E(1-e^(-t/T)) Where T=Tau=RC, E is the Voltage of the power source, and V is the voltage of the capacitor...
Homework Statement
Derive the Voltage and Current equations for Step Response of an RC circuit.
Homework Equations
End products will be Vc(t) = i(s)R + (Vo - i(s)R)e^(-t/RC) and i(t) = (Is - (Vo/R))e^(-t/RC)
The Attempt at a Solution
Using KCL on a hypotetical RC circuit with a...
Homework Statement
This isn't really a homework question- at the end of my last lab, in which we measured the time required to charge and drain a 10micro farad capacitor with a 100k resistor hooked up to a switch and a 9 volt battery our professor asked us what the natural log of voltage...
Homework Statement
Design a RC circuit so it has the same V vs time characteristics
*See attached diagram*
Homework Equations
The Attempt at a Solution
I really have no idea how to approach this, but I do know,
RC circuit:
Vc(t)=Vb(1-e^-(t/RC))
RL circuit...
Homework Statement
Design an RC circuit that has the same Voltage vs. Time characteristics as the RL circuit shown
*See attached Diagram*
Homework Equations
The Attempt at a Solution
Not really sure how to approach this, but all i know is the equations:
RC circuit...
Homework Statement
Sketch a graph of Vout vs time after the switch is closed
*See attached diagram*
Homework Equations
The Attempt at a Solution
I am not really sure how to do this, because I don't know if it makes a difference whether or not the resistor is before the...
RC Circuit, Finding Frequency? [Solved]
Solved =]
Homework Statement
Homework Equations
Z = [ R2 + (1/wC)2 ]1/2
where Z is impedance, w = (omega) = angular frequency
Xc = 1/(wC)
w = 2(pi)f
(tau) = RC
where (tau) is the time constant
The Attempt at a Solution
I'm more confused than...
Homework Statement
The bit I'm struggling with is to determine the time constant \tau for the referenced circuit after the switch is closed. Constants are given in the image, which can be found at https://www.physicsforums.com/attachment.php?attachmentid=12737&d=1203627574.
Homework...
Hello,
The circuit attached below is from Richard Dorfs Intro to Electric Circuits book. The switch is shut for a long time and opened at t=0.
The question asks to find the i(t) across R11, which they use nodal analaysis and find it to be 66.67 - 16.666 e^{-t/120} micro Amps, where 66.67 micro...
In my book (Storey), there's an exercise with a parallel RC circuit, where R = 80 Ohm and C = 30 uF. The answer for the complex impedance is supposed to be 40-j40, however I can't seem to get there! I've showed my working under. Am I doing something wrong, or is the book's answer wrong? (freq...
Hello,
is it possible to write a Lagrangian (L) for a simple RC (or RL) circuit?
Normally L = kinetic - potential energy, but how would you write
this for an RC circuit?
thanks!
Homework Statement
The switch in the following circuit has been opened for a very long time and then closes at t=0 (a) Calculate Vc(t) for t>0. (b) Calculate i(t) for t>0.
Homework Equations
The Attempt at a Solution
Here is my attempt of the problem. I have not dealt with a...
Homework Statement
An RC circuit is made of a 2.2 kOhm resistor and a 0.001 microF capacitor.
The circuit is connected to a 10V source of emf for 5 x 10^-5 s. What is the
resulting charge on the capacitor after that?
Homework Equations
Q(t) = -ECe^(-t/RC) + EC , where E is the emf...
Hi there,
I have a circuit in which consists of a resistance (rs) in series with parallel combination of capacitor and resistance(rc). I want to calculate value of rs. So i did this by calculating total impedance Ztotal which is V/I and then substracting impedance of parallel rc circuit...
I am trying obtain some equations for an RC circuit that has a resistor R1 after a battery, which then splits into a capacitor C and a resistor R2 (the circuit closes after this point).
When I try to seek help online, the resources are quite unhelpful. I cannot seem for example, obtain any...
Homework Statement
this was a practical examination given to us.
[connected to CH1]
|----(1.8k ohms)-----|
|aaaaaaaaaaaaaaaaaa|
|aaaaaaaaaaaaaaaaaa(unknown resistance) [these 2 unknowns are ch2]
(~)aaaaaaaaaaaaaaa|
|aaaaaaaaaaaaaaaaa(unknown capacitance)...
Homework Statement
I want to find ix in the circuit below when the switch opens at t=0 after having been closed for a long time.Homework Equations
v(t) = v(infinity) + (v(0)-v(infinity))e-t/RC
i(t) = C dv(t)/dt
ix = isource - i(t)
v(t) = voltage across capacitor
i(t) = current through...
Homework Statement
The switch in the circuit has been closed for a long time, and it opens at t = 0. Find v(t) for T \geq 0.
http://img834.imageshack.us/img834/9107/tutorialq2.jpg
Homework Equations
V(t) = Voe-t/RC
\tau = RC
The Attempt at a Solution
@ T<0
Short Circuit due to capacitor
V =...
Homework Statement
The switch has been in position 1 for a long time before moving to position 2 at t=0. Find i(0) for t>0.
Image of circuit:
http://img215.imageshack.us/img215/9200/circuit3.png
Homework Equations
KVL
First Order Diff Eq
The Attempt at a Solution
So to start...
Homework Statement
For the RC Circuit (R = 100 Ohm, C = 100 Micro Farads, and an open switch at t=0), we know that the capacitor is charged to a voltage of 10 V prior to T=0.
Find expressions for Vc(t) and Vr(t).
Homework Equations
Vc(t) = Vi * e(-t/rc)The Attempt at a Solution
Vc(t) =...
Homework Statement
Find the time constantHomework Equations
T=RC
The Attempt at a Solution
I understand the calculation fine. But I was wondering if the resistors are considered to be in parallel with each other even though the second resistor appears to be in parallel only with the...
Homework Statement
I am given an RC circuit with an alternating current. The circuit contains a capacitor and a resistor in parallel. Part (a) says "Use KCL to find a differential equation for I in terms of V." Part (b) says "For an applied voltage V = Voexp(iwt), find the current I."...
http://www.screencast.com/users/trinhn812/folders/Jing/media/de5edaba-e848-47f5-82b9-bd770b216e95
I need help with Question 27 specifically. The correct answer is A, but I don't understand why.
I thought it would be B according to Korkoff's Loop rule of the inner left loop, where current...
Hello all!
I am really stuck up here. I have made this circuit and want to measure the voltage across the capacitor. The voltage should gradually increase as the capacitor charges, and then become constant. But, I only get a constant voltage of 6V across the capacitor.
Infact, I have to...
Homework Statement
Pls see the attachment.
Homework Equations
The Attempt at a Solution
Obviously I have B and C correct but for a the only thing I can find is tan(phi)=XL-Xc/R
This seems to be for a series RLC circuit though and I only have RC.
also I know that the current lags...
My first post!
Question: Is a general RC circuit, with any topology of interconnected R and C elements, never underdamped?
This is a bonus question in one of my homeworks. The answers to the earlier questions in the problem indeed show that two example RC circuits are not underdamped.
I...
When a capacitor is charged by a battery half the power is dissipated as heat and half is stored as potential energy within the field of the capacitor. Similarly a resistor dissipates all power that the battery supplies.
Now here's my question: In an RC circuit where is the power dissipated...
The following circuit is given:
[PLAIN]http://img822.imageshack.us/img822/6369/image2lz.jpg
Switch S is closed until the charge q2 on C2 reaches its maximum, then at t=0 the switch is opened. Find q1(t).
Using Kirchkoff's rules I found:
EMF= (q1)/(C1+I2R
I2R= q2/C2
I1= I2+I3
In order to...
Hi everyone...
I need to solve the differential equations of a RC circuit given a voltage and a current pulse. I have to get this responses:
http://i.imagehost.org/view/0340/Respuesta1
I'm using matlab, with runge kutta. I've been solving the equations separately changing the initial...
Homework Statement
I have the circuit that's attached as a .bmp image. I'm asked to find the initial current that passes trough the battery (V=60 V) knowing that the capacitor is initially charged with charge q_{0}=0.1 C. The resistances are R_1=R_2=R_3=1 Ohm and C=1/1000 F.
Homework...
Thank you ZapperZ for introducing these new peer-review papers.
This one is of particular interest to me.
I believe I may have some insight into this issue.
In the normally constructed RC circuits using discrete components, the reactions of the individual components to signal frequency...
When a capacitor discharges, the potential difference between its plates and the resistor's terminals is the same. Hence,
\frac{Q}{C}=R \frac{dq}{dt}
Solving this equation we get
q(t)= Q_{0} exp \frac{t}{RC}
Obviously, this isn't the solution. It is actually q(t)= Q_0 exp...
I know that T = RC
I've tried different combinations of R (not really sure what Req to take) but none of them worked. Any one can show me the right way ?
Homework Statement
I'm confused by the interpretation of the charging and discharging formulas:
Charging: Q= Qo (1-e^-t/RC)
Discharging: Q=Qoe^(-t/RC)
Like for Qo, like apparently its the max charge, so does that mean at the very end of charging? Initially, i thought that Qo meant that the...
Homework Statement
A 10.0 microfarad capacitor is charged by a 10.0 V battery through a resistance R. The capacitor reaches a potential difference of 4.00 V in a time interval of 3.00 s after charging begins. Find R.
Homework Equations
The Attempt at a Solution
So basically i got...
The question asks to derive the equation you need to find the resistance of a voltmeter in a simple RC circuit like the one shown here:
http://people.ee.duke.edu/~cec/final/node32.html
But R2 in the link is actually a capacitor in my circuit.
The equations in the lab journal are
Vc=q/C...
Homework Statement
What is the charge on the capacitor?
Homework Equations
Kirchoff's rule
change in V =q/c
The Attempt at a Solution
I want to use Kirchoff rule but I don't know if this is the right way to go.
Homework Statement
A 1234. pF capacitor and a 5.6 × 106 ohm resistor are connected in series to 78. volts EMF. Approximately how long does it take the capacitor to become almost fully charged?
Homework Equations
Vf=Vo(1-e^(-t/RC))
The Attempt at a Solution
I'm not sure if the...
Homework Statement
What is the voltage across a capacitor after a time of two constants when charging from zero voltage. When discharging from a fully charged condition?
Homework Equations
VCapacitor = VBattery(1 - e-t/2T)
VCapacitor = VMaximum * e-t/2T
The Attempt at a Solution
I'm...
Homework Statement
The capacitor in the circuit has 537 μC of charge on it at t=0. The resistor is 1,923 Ohms, and the capacitor is 1,251 microFarads
How long will it take for the charge on the capacitor to drop to 195 μC?
Please use only SI (metric) system units in your answer...
Homework Statement
I have an RC Circuit. There's the EMF (voltage supplier; battery), a resistor, and a capacitor. They are all in series. I need to prove that
--the energy stored in the capacitor through it charging equals 1/2 the energy supplied by the EMF
Then I need to show
--how much...
RC circuit - charge on capacitor after a "long time"
Circuit: 10V goes to 100ohm resistor, then there's a branch point. One side leads to a a resistor R2 = 100ohms and the other to a capacitor with C = 1uF. The switch is located just before R1, and is closed for a "long time."
Solution: Ok...