Rc circuit Definition and 396 Threads

Homework Statement The figure shows the circuit of a flashing lamp.There is a current through the lamp (see the photo) only when the potential difference across it reaches the breakdown voltage VL; the capacitance DIScharges completely through the lamp. (a)A lamp has breakdown voltage...

In an RC circuit, the phase angle between the input and output voltages (not current and voltage) seems to be proportional to the amplitude of the output voltage. That is, as the phase angle between input and output goes to plus or minus 90 degrees, the output voltage goes to 0. Why is that?

Homework Statement Ok guys, so this is a slightly long question, but bear with me because I think I figured out most of it. I just need help towards the end. So I have a circuit with a current source in parallel with a capacitor and also in parallel with a resistor (see attached image). This...

Homework Statement http://imgur.com/OowiMCR As noted in the image: In the circuit below, R1=R2=10kΩ, and C=0.1μF. Plot Vout(t) if the input, Vin, is a step function of height V0 at t=0 Homework Equations Vcap=V0-Ce-t/RC The Attempt at a Solution I was hoping someone could...

In lectures I covered how a Schmitt trigger can be used in an RC circuit to determine the capacitance of the capacitor (Where the Schmitt trigger switches at 0.3V+ and 0.6V+). The equation given was that C = 1.2 R \ T (time period) Does anyone know how to derive this or where it comes from...

Homework Statement Use current equation and find di/dt expression, hence show if initial gradient were maintained the current would be 0 after 1 time constant. Homework Equations I calculated RC to be 0.5s i=0.02e^-t/0.5 The Attempt at a Solution I solved di/dt to be...

Homework Statement Homework Equations w = 1 / sqrt(LC) The Attempt at a Solution hi there, I 1. I decided to choose, 93.3 MHz so 93.3 x 10^6 Hz is my freq. 2. I googled how a band pass filter diagram should look like and I found this, is the only way to create a low...

Homework Statement A 140μF defibrillator capacitor is charged to 1500 V. When fired through a patient's chest, it loses 95% of its charge in 40 ms. What is the resistance of the patient's chest? Homework Equations The Attempt at a Solution According to "Mastering Physics," the solution that...

I bought a biophysics book the other day, and immediately began reading it. Sadly, I'm only 12 pages in now, because I seem to have run up against a wall in my understanding. You see, I don't understand a step being taken in the math, and am not sure what I should learn to understand it better...

Homework Statement C1= 2.0 μF C2= 5.0 μF the resistor has a resistance of 0.10 MΩ The circuit shows the charging of a capacitor a) At t=0 the switch is closed. What is the initial measuring on the ammeter? b) After the current has decayed to zero what are the voltages at points A,B and C...

Homework Statement Given V R C for the figure, determine a. The voltage of a with respect to b when the switch is open? b. Which point a or b is at a the higher voltage? c. What is the final voltage of point b with respect to ground when the switch is closed? d. Wow much...

Homework Statement Task is to write differential equation for this circuit. Homework Equations The Attempt at a Solution I'll try to solve the task, but now I want to know, is it possible to use voltage source instead of current source. For example, I can calculate ekvivalent...

Homework Statement Signals from sources of different kinds are often very weak and very quick. To minimize the noise risk they're often led through coaxial cables. How long can one [coaxial cable] be if it has the capacitance 80pF / m and resistance 0.04 Ohm/m and you want to transfer noise...

Hi, Basically I have circuit with an input Vi (s) across a capacitor C which is in parallel with a resistor R1. And these 2 components are in series with another resistor R2 (please see attached drawing). The question states: Show that the transfer function of the circuit is: Vo/Vi...

Homework Statement A capacitor C=8.00*10^-8F which has an initial charge q=1.4*10^-6C starts to discharge through a resistor R=3.00*10^6Ω at time t=0. Determine the total energy W dissipated as thermal energy in the resistor. Hint: use energy conservation. The Attempt at a Solution I...

I'm having a hard time understanding and solving problems in moderately complex RC circuits... Please Help. You don't have to solve right up to the numerical value, that is not my priority, Rather If you could just explain how to begin and process through the question, It would be best...

I'm having a hard time understanding and solving problems in moderately complex RC circuits... Please Help. You don't have to solve right up to the numerical value, that is not my priority, Rather If you could just explain how to begin and process through the question, It would be best...

Hello I have a conceptual question about using Kirchhoff's voltage rule to derive expression of the charge in the RC series circuit when it is being charged by certain EMF. Usually most books start by writing the equation \mathscr{E}-iR-\frac{q}{C}=0 But when the charging is going on...

Homework Statement Can a series RC circuit and a parallel RL circuit have the same impedance if the R is the same in both? What would the values of R, L and C have to be if they can? Why/why not, physically speaking? Homework Equations Zr=R Zc=1/iwC ZL=iwLThe Attempt at a Solution I know in...

Homework Statement A simple RC circuit with an EMF source ε, Resistor R and capacitor C are in series. When the switch is closed find the rate of energy stored in the capacitor, the power dissipated in the resistor, and the power supplied by the emf as functions of time. Homework Equations...

Homework Statement For the multi-loop circuit as shown, assuming the capacitor is initially uncharged, find the currents in each of the resistors at t=0 after the switches are closed. So I believe there are 8 unknowns really because of the 8th branch with the capacitor. If you look at the...

Homework Statement Switch is initially opened with the capacitor uncharged. At t=0 the switch is clsoed. At time=t1 later, the potential difference between A and B is 2.00volts Find the charge on the capacitor at time t1. R=10,000ohms C=2.4nF Vb=12volts VA->B-=2.00volts Homework...

Homework Statement How much time does an RC circuit require to become fully charged assuming that the capacitor was initially uncharged. resistance = R capacitance = C Voltage = V Homework Equations Q=CV(1-e^(-t/RC)The Attempt at a Solution so T = -ln(Q/(CV) - 1)RC but Q = 0 since it's...

Homework Statement A 10-µF capacitor is charged by a 10-V battery through a resistance R. The capacitor reaches a potential difference of 4 V in a period of 3 s after the charging began. Find the value of R.Homework Equations c=q/v q=CE(1-e^-t/RC) i=(E/R)e^(-t/RC)The Attempt at a Solution I...

Homework Statement Uploaded problem 5 Homework Equations i1=(R2/(R1+R2)) i2=(R1/(R1+R2)) The Attempt at a Solution Are my answers for problem 5 ok?

Hello, I know that if two resistors are in parallel or two capacitors, they have the same voltage. However, is it the case that a resistor and capacitor in parallel also have equal voltage?

Homework Statement http://img163.imageshack.us/img163/6339/rccircuit.png Homework Equations The Attempt at a Solution I'm trying to find the node voltage. I was going to try and solve the problem knowing that the net charge is zero. Q = CV I'm having problems the voltage...

Thanks, solved!

Homework Statement I'm trying to use the equation for charging capacitor that's discharging, and I can't get the answer right. On the calculator it keeps showing as 1.Homework Equations I(t) = -(1.96) [e^((-9.0*10^(-6)) / (1300)(2.0*10^(-9)))]The Attempt at a Solution My problem is that the...

Homework Statement after having been in position 1 for a long time, the switch was moved to position 2 at t=0. determine: a) i-c(0-) and vc(0-) b) i-c(0) and v-c(0) c) i-c(infinity) and v-c(infinity) d) v-c(t) for t>=0 e) i-c(t) for t >=0Homework Equations The Attempt at a Solution not sure...

Homework Statement Please look at the attachment for the circuit. The question is this: The switch has been closed for a long time. It is then opened. How long does it take for the potential across the 4μF capacitor to fall to half of its initial value? Homework Equations V =...

Homework Statement A circuit is constructed with four resistors, one capacitor, one battery and a switch as shown. The values for the resistors are: R1 = R2 = 52 Ω, R3 = 41 Ω and R4 = 129 Ω. The capacitance is C = 62 μF and the battery voltage is V = 24 V. 1) The switch has been open for a...

In a series RC circuit, the current flows until the voltage of the capacitor equals that of the source so that the two voltages oppose each other and there's no net flow. In a parallel circuit, the current indeed does stop flowing through the branch the capacitor is attached to (after the...

http://i.imgur.com/ZCcaZpq.png I have the solution manual, so this is more just a question of why, rather than what. I understand that with the switch open: vA = 3v vB = vC = 0v i0 = 0.25 mA When the switch closes it creates a short that makes the two 6kΩ resistors irrelevant...

So we're covering RC circuits in my physics class and I'm having some trouble with the concepts. When you have a circuit with a resistor and a battery, current passing through the resistor produces a voltage drop. If the battery is zero for our potential, the battery imbues the circuit with...

Homework Statement http://imageshack.us/a/img831/8798/homeworkprobsg31.jpg Assuming that the switch has been in position #1 for a long time; at t = 0 the switch is moved to position #2. Calculate the current i(t) for t>0.Homework Equations Q = CV V = IR V(t) = -V0*e-t/RC (V0 is the...

Homework Statement What is Q(∞), the charge on the capacitor after the switch has been closed for a very long time? a circuit, whose image is attached, has known values for the resistors : R1 = R2 = 72 Ω, R3 = 101 Ω and R4 = 79 Ω, is C = 56 μF, V = 24 V. Homework Equations kirchoff's laws...

Homework Statement i tried using the usual Q=VC to answer this question for a multiloop RC circuit, "What is Q(∞), the charge on the capacitor after the switch has been closed for a very long time?" and my answer was wrong. clearly, i can't find Qmax because the resistors contribute to the...

Homework Statement A circuit is constructed with four resistors, one capacitor, one battery and a switch as shown. The values for the resistors are: R1 = R2 = 22 Ω, R3 = 91 Ω and R4 = 129 Ω. The capacitance is C = 40 μF and the battery voltage is V = 12 V. The positive terminal of the battery...

Homework Statement Consider a series RC circuit with R = 151 Ω and an unknown capacitor C as shown below. http://www.flickr.com/photos/67342906@N0… The circuit is driven by an alternating electromotive force with εRMS = 174 V at a frequency of f = 7.70 Hz. The current in the...

Hello, I'm trying to analyze the RC circuit... specifically a low-pass filter, so the set up is voltage source to resistor to capacitor, and the voltage source provides an oscillating voltage Vin, whereas I measure Vout across the capacitor. I think I'm getting confused between two different...

Homework Statement This isn't a problem from a textbook, but it is homework. For a lab in class, we worked with simple RC circuits on breadboards. The strange thing I noticed is that the capacitor always charges faster than it discharges. I know that the Time constant should be T=RC, so I...

Homework Statement Find the phase angle between the input and output voltages in the following two circuits - in each case state whether the output leads or lags the input voltage. The second circuit is the same but the capacitor and the resistor are switched around. Homework Equations...

I have a series rc circuit. 80 v battery, capacitor1, resistor1: 10M ohm, capacitor 2, then back to the negative end of the battery. Capacitor 1 and 2 are equal, after a certain time, the voltage on each capacitor is 40.0v. What is the capacitance of each capacitor? Thanks!

Homework Statement In the following transient circuit, assume at t<0, the circuit is at steady state. Find i0(t) for t>0 http://sphotos-b.xx.fbcdn.net/hphotos-ash3/c0.0.241.241/p403x403/521743_510378412315012_79982992_n.jpg Homework Equations The Attempt at a Solution First...

Homework Statement The Attempt at a Solution I tried two different methods and came to an odd conclusion:

Homework Statement Consider the circuit below, where C1=80mF, C2=30mF, R=50ohms and E=5V. At t=0, both capacitors are uncharged - so it's charging. The circuit is in series, with E ---> C1 ---> C2 ---> R ---> (back to) E a) Find the time constant. b) The initial potential...

Homework Statement Determine the value of the current labeled i and the voltage labeled v at t=0+, t= 1.5 ms, and t = 3.0 ms. Homework Equations Ohm's law: v = i *r Decay in source free RC Circuit v(t) = v@0 * e^(-t/RC) The Attempt at a Solution i(0-) = 0.1 A. Therefore, v across 200 ohm =...

Homework Statement An RC circuit has EMF=12.0V, R=15 kΩ and C=3.8 μF. How long does it take for energy stored in the capacitor to reach 65% of its maximal value? Homework Equations 1) Q = Cε 2) Q X .65 = desired charge 3) q(t) = Q(1 - e-t/RC) The Attempt at a Solution This is...

Homework Statement When the cehicl stop's in the team's pit stop, consider the time as being t=0. If the potential difference between the car and ground is 30kV, the car-ground capacitance is 500pF and the resistance of each tyre is 100Gohm, determine the time it takes for the car to discharge...