rc (for "run commands") is the command line interpreter for Version 10 Unix and Plan 9 from Bell Labs operating systems. It resembles the Bourne shell, but its syntax is somewhat simpler. It was created by Tom Duff, who is better known for an unusual C programming language construct ("Duff's device").A port of the original rc to Unix is part of Plan 9 from User Space. A rewrite of rc for Unix-like operating systems by Byron Rakitzis is also available but includes some incompatible changes.
Rc uses C-like control structures instead of the original Bourne shell's ALGOL-like structures, except that it uses an if not construct instead of else, and has a Bourne-like for loop to iterate over lists. In rc, all variables are lists of strings, which eliminates the need for constructs like "$@". Variables are not re-split when expanded. The language is described in Duff's paper.
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...
greetings,
At high frequency (more than 20kHz) the reactance of capacitor is very small and act as short circuit.this increase the loading of next stage.whats the meaning of increse of loading in next stage?
RC coupled two stage amplifier circuit is here-...
In an RC circuit shown below, with the switch closed after a long time, when the capacitor is charging, there is a current across the capacitor given by Initial current x e ^ (-t/RC)...
Is this current...the current supplied by capacitor to the rest of circuit, or simply the current across...
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...
I've been trying to answer the following equation but I just can't get my head around it!
'calculate the time taken 't' for the voltage over capacitor array (Vc) to reach 80% of Vo, in terms of Vo, R, C1 and C2 (caps are in parallel)'
I know I need these two equations but I just don't...
Hi,
Is there a possibility of getting a complex conj zeros in pure RC ckt.
we never get complex conj poles but how about complex conj zeros.
regards,
Asif
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!
Bear with me:
When the frequency is low in an RC series circuit and we take the voltage across the capacitor, the capacitors reactance is high and thus most voltage is across it. But when the frequency is high, the reactance goes down, and little to no voltage is dropped across the...
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 =...
I was trying to figure out the relation between the equation of a discharging capacitor and the Natural Inverse Exponent function
v(t) = Vo*e^(-t/rc)
A*e(-Ct)+B
I get that A represents the voltage and the C is the inverse of the time constant but i can't figure out what the B stands for
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) =...
I was wondering how you could turn an RC aircraft out to a water bomber?? I thought of installing a container in the fuselage where water could be filled but can't think of how to get water out. Any suggestions on that or any other ideas of loading the water?
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...
1. Homework Statement
Find the voltage across a capacitor in an RC Circuit, using [V]_{}[/c] (0) = 1, [V]_{}[/i] n(t)=t.
2. Homework Equations
dV/dt = (1/RC)(V)=(1/RC)([V]_{}[/in])
3. The Attempt at a Solution
New to this site: I honestly don't know where to start. Done well in...
Homework Statement
Find the voltage across a capacitor in an RC Circuit, using [V]_{}[/c] (0) = 1, [V]_{}[/i] n(t)=t.
Homework Equations
dV/dt = (1/RC)(V)=(1/RC)([V]_{}[/in])
The Attempt at a Solution
New to this site: I honestly don't know where to start. Done well in Calculus...
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...
I recently extracted the control system out of a severely damaged RC aircraft (a very simple kit deal). It's got two servos, and a pretty good motor, which works out perfectly for me!
I want to build a new aircraft from scratch using the recovered control system. For the fuselage I'm...
Homework Statement
the title says it all, we are required to show that the units of RC are the same as the units of time.
ie. iohm * 1 farad = 1 seconds
Need help
thanks
Homework Equations
The Attempt at a Solution
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...
For an RC aircraft which i am working on i was thinking about having static stability at the extreme limits of pitching to prevent stalling and further instability, but i was wondering what to have between the limits neutral static stability or static instability. Static instability may help the...
hello friends...
i am having following problem in this question.
first i don't understand how they have calculated R equivalent=5/6.i think its value should be 25Kohms. will it be different at 1ms and 4ms or same ?\\
i shall be thanks to u .
in one picture is the problem n in other...
Homework Statement
I'm a bit confused about how to find the phase equation of a lossy low pass filter
eg.
Homework Equations
For a normal low pass filter it's just arctan(wRC)
The Attempt at a Solution
So I am comparing this by subbing in values and comparing to a bode...
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
In an RC discharge circuit, R= 2.5 X10^4 ohms and C=40 microfarad. The initial potential difference across C is 25 V. Find the rate at which energy is being lost by C at 0.5 seconds.
Homework Equations
The Attempt at a Solution
Like in this case, I probably have...
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...