# Rc circuit Definition and 43 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.

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1. ### I Electronics experiment boards -- What experiment can I do with these?

I recently got these electrical experiment boards to do some experiments but I am new to doing experiments with such boards. Can someone help? Thanks in advance https://ibb.co/zXTbNby https://ibb.co/tDjKrV0 https://ibb.co/JdCTgqY https://ibb.co/DDkGjbp
2. ### RC Phase Shift Oscillator not Oscillating

Hello everyone. I am having some trouble with an RC phase shift oscillator that I built as a hobby project. I am completely stuck on this and I just cannot figure it out. My oscillator is not oscillating. Here is the circuit that I am trying to get to work. Taken from...
3. ### Engineering Frequency Response Between 100Hz and 100kHz

So am trying to find the Frequency response of a RC LPF between frequencies 100Hz-100kHz ,but i don't know what formula to use .
4. ### Engineering AC transient in an RC circuit

Here, at voltage source zero crossing, cos(2to + pi/4) =0. So, 2to+pi/4 = pi/2 This gives to=pi/8 = 0.3926s. But the given answer is twice the answer I got i.e. 0.7852s. Have I missed anything here?
5. ### Time constant for parallel RC circuit

Homework Statement Question 6. Homework Equations Time constant = RC The Attempt at a Solution I think answer should be 1/2 RC as Rnet = 1/2R and to convert it to single resistance form we should first find Rnet But the answer is coming out to be RC . How? << Corrected Image added by...
6. ### Engineering Find the time constant for this RC circuit, help please

Homework Statement Homework Equations The Attempt at a Solution
7. ### Engineering RC Circuit/Node voltage question

Homework Statement Homework Equations The Attempt at a Solution So you need to find the voltage across node D while the capacitor is charging, so it is going to be related to the voltage of the capacitor, so a function of time, so you need to come up with the equation for Vc(t), which I...
8. T

### Current at resistor 2?

Homework Statement In Fig. 27-66, R1= 10.0 kΩ, R2 = 15.0 kΩ, C = 0.400 µF, and the ideal battery has emf E = 20.0 V. First, the switch is closed a long time so that the steady state is reached. Then the switch is opened at time t = 0. What is the current in resistor 2 at t = 4.00 ms? This is...
9. ### RC Circuit Discharging

Homework Statement At initially, the switch is open meaning there is no current flowing. So how does the capacitor is initially charge to -5V? and what does a negative voltage capacitor means? I thought it is only when the switch is closed (t=0) that when the capacitor is being charged...
10. ### Capacitor Equations

Homework Statement Hi, I've run into two different equations for the voltage of a typical RC circuit, one resistor, and one capacitor. Please explain the different between the two. One has a 1 - the natural log and the other one doesnt. Homework Equations 1. V(t) = Vo*e^(-t/RC) 2. Vc =...
11. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

Homework Statement [/B] Derive an expression for vc(t) in the circuit of Figure P4.13 and sketch vc(t) to scale versus. I attached a screen shot of the circuit for this problem. time. Homework Equations V = IR V = V0exp(-t/tau) The Attempt at a Solution [/B] I am trying to find the...
12. ### Discharging capacitor in RC circuit, confusing path

Homework Statement The circuit in the figure below has been connected for a long time. Let R1 = 8.20 Ω and R2 = 4.40 Ω. (a) What is the potential difference across the capacitor? (b) If the battery is disconnected from the circuit, over what time interval does the capacitor discharge to...
13. ### RC Circuit and current from a discharging capacitor

Homework Statement In the circuit of the figure below, the switch S has been open for a long time. It is then suddenly closed. Take = 10.0 V, R1 = 56.0 kΩ, R2 = 200 kΩ, and C = 14.5 μF. (a) Determine the time constant before the switch is closed. (b) Determine the time constant after the...
14. ### Figuring out why experimental results are different

Homework Statement Hello everyone, I am trying to figure out how to approach part c, parts i and ii Homework Equations OK. I know that we have the current equation in milliamps as shown above The Attempt at a Solution My problem is giving one possible explanation for the finding and...
15. ### Need help with voltage across a capacitor in a DC circuit

In a RC circuit is voltage through a capacitor always consider negative no matter if you're going with or against the current when setting up a voltage equation?
16. ### Engineering DC state RC circuit Find Vc(0)

Homework Statement Find Vc(0) Homework Equations Nodal Eq , ohms law The Attempt at a Solution Can someone please check my work for Vc(0)? I'll appreciate it.
17. ### Nodal Analysis: please check my work

Homework Statement Find Vc(0) Homework Equations Nodal analysis The Attempt at a Solution
18. ### Engineering RC circuit problem

Homework Statement 2. Homework Equations [/B] KCL, Node Analysis , Mesh Currents The Attempt at a Solution Hi, in part b when t>0 the capacitor is replaced by an open circuit , however in part c the capacitor is replaced by a short circuit why is that?Aren't inductors the only ones...
19. ### How to graph amplitude vs. frequency for a Low-Pass Filter?

Homework Statement For my lab class my professor wants us to graph the theoretical amplitude of the output from a low-pass filter vs. frequency. I have the resistance and capacitance that I chose for the RC circuit and a V(in). Is there an equation that I should be able to use to relate these...
20. ### RC circuit, finding voltage across a capacitor

Homework Statement I am trying to find the capacitor voltage in the following picture: Find i(t) in the figure below. Assume dc steady state conditions are valid for t<=0. Homework Equations i=c(dv/dt) KCL The Attempt at a Solution At t<0 I found Vc to be 8 volts which should be correct...
21. ### The battery equivalent internal impedance equation

Homework Statement Hello, long story short: I need to create a model of Li-Ion battery and I'm stuck on calculating the battery equivalent internal impedance. The thing is, I don't know the equation or even how to make one. However, I have a circuit drawing: Homework Equations Values in...
22. ### Engineering Impedance angle in RL and RC circuits

Homework Statement This isn't so much of a problem itself but I found it interesting that on the All About Circuits website, two of the questions give a phase angle for impedance as opposite the angle of current. I understand the current is 90 degrees out of phase with voltage in both RL and RC...
23. ### Engineering 2 Loop RC Circuit 2

1. Situation and Variables: A circuit is constructed with four resistors, one capacitor, one battery and a switch as shown. The values for the resistors are: R1 = R2 = 30 Ω, R3 = 66 Ω and R4 = 113 Ω. The capacitance is C = 64 μF and the battery voltage is V = 12 V. The positive terminal of the...
24. ### Circuit with three capacitors

Homework Statement A potential difference of V = 38.0 V is applied across a circuit with capacitances C1 = 4F, C2 = 5F, and C3= 2F, as shown in the figure. What is the magnitude and sign of q3l, the charge on the left plate of C3 (marked by point A)? What is the electric potential difference...
25. ### How I find value of U on R2 long time after switch is closed

https://qph.is.quoracdn.net/main-qimg-c22d8aa4be4fc2ed9b2f1c7060982e04?convert_to_webp=true [Broken] How to find value of U on R2 long time after switch is being closed? Capacitors are charged so there is no current going through? Or? I used kirchof rule so i get Uo+Uc1-U=0 U=Uc1+Uo...
26. ### RC Circ, Capacitor charging Q....very lost

Homework Statement Homework Equations Series: R_{eq} = R_1 + ... + R_n Parallel: R_{eq} = \left(\frac{1}{R_1} + ... + \frac{1}{R_n} \right)^{-1} Charging Capacitor: I = I_0 e^{-t/RC} Charging Capacitor: \Delta V_C = \varepsilon (1- e^{-t/RC}) Charge: Q = C \Delta V_C The Attempt at a...
27. ### Solving an RC circuit using explicit euler

Homework Statement Hi there. I have a simple RC circuit with a battery voltage of 10 V, R = 1 Ω, C = 1 F and a switch. I want to use the Explicit Euler (forward divided difference) to solve the equation and check for stability, rather than using a ODE. I am finding the equation for when the...
28. ### RC oscilloscope

How can a time constant, in parallel plates, be the original value without changing the capacitor?
29. ### ODE RC Circuit Problem

Homework Statement Suppose an RC series circuit has a variable resistor. If the resistance at time t is given by by R = a + bt, where a and b are known positive constants then the charge q(t) on the capacitor satisfies (a+bt) q' + (1/C)q = V where V is some constant. Also q(0) = q_0 Find q(t)...
30. ### Electricity and Magnetism RC Circuit Conceptual Questions

Edit: sorry i realized i posted this in the wrong section. Can some move it to hw? Thank you. Hey i was studying intro E&M recently and i started learning about RC circuits. Up until this point everything, concept wise, has made sense for me. Then I learned how RC circuits work, and the math...
31. ### Voltage across resistors in RC circuit

Homework Statement Calculate the voltage, current, and power across the two resistors for every second of run 1 in the RC circuit. The RC Circuit: The settings of the circuit: The Graph. The capacitor is charged until it reaches 5.0 V and then discharged until it reaches 1.0 V. This...
32. ### Parallel Plate Capacitor with variable Dielectric (water)

Hi everyone. I have a problem with my device. It consists of a parallel plate capacitor with plates made of galvanized iron. Each plate's area is 1mx1inch. It's connected to a bleeder resistor and basically, the circuit is just a simple RC circuit. The source I'm using is a constant 5V DC...
33. ### Question on capacitors in an RC circuit

Homework Statement All information is given in the picture posted Homework Equations V=IR , Q=CV The Attempt at a Solution What I don't understand is , when the capacitors are initially uncharged , they should just be treated as wires , if this is the case , then the entire circuit is...
34. ### Engineering RC circuits, a step skipped in solution

Homework Statement . [/B] This is problem 7.45 in Fundamental of Electric Circuit 5th edition. 2. Homework Equations First off, I want to go ahead and say that I don't need the solution I already solved it. I went ahead and used Nodal analysis when Vs = 30. I placed a node voltage right...
35. ### RC Circuit current help

Homework Statement Homework Equations ##q = Q(1-e^{\frac{-t}{RC}})## The Attempt at a Solution Don't know where to start...
36. ### Graphing Current v. Time for simple 2R1C circuit

1. Homework Statement The switch is closed. Graph the current in R_{1} 2. Homework Equations V = IR CV = Q 3. The Attempt at a Solution 1) R_{0} can be ignored a) The resistor simply reduces the voltage before any current can be split. b) We're justified, as a result, in...
37. ### Obtain Expression For Voltage Across Capacitor

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)##...
38. ### Turning a PART of electrical into mechanical energy

So I am awere of everything in electromagnetism in physics,but lately I am enjoying in creating RC cars.But I only got to making a car going only forward,how can i make him turn?How could I transform only a part of the electrical energy into mechanical so that my RC car can turn left and right...
39. ### RLC Circuit Frequencies Help

Homework Statement In each of the four circuits shown, an AC input voltage, ##V_0 cos(\omega t)## is applied on the left and the output voltage is measured on the right. Treat the input frequency as a...
40. ### RC Circuit Help

Homework Statement There is a circuit with a battery of voltage V and resistor R, then splits into two branches one with a capacitor C, and one with a resistor 2R. The answers for the questions can only depend on R, C, V, and t. When a switch only allows current to flow through the capacitor...
41. ### Diffifult RC Circuit

Find the potential of point a with respect to point b in the figure (Fighttps://s.yimg.com/hd/answers/i/1ffe0f8aeaf145679cde38f7812b1c7f_A.png?a=answers&mr=0&x=1413484693&s=0943630e47eb74ae023909f7d39f74e3 [Broken] ure 1) . If points a and b are connected by a wire with negligible resistance...
42. ### Alternating currents circuits

Homework Statement part 1 Consider the circuit of figure G, where R1=20 ohms R2=10 ohms X1=37.7 ohms X2=-53.1 ohms. Compute the current and the phase angle between the current and the applied voltage. In the figure R1 is in series with X1 and R2 and X2 are in series. R1 and X1 are in parallel...
43. ### RC Circuit with alternating voltage source

Homework Statement I'm supposed to find the current in a circuit with a voltage source, capacitor, and resistor in series. The voltage source is described by V=V0ejwt. Here, j is the complex number j2=-1, and i is the current Homework Equations I=C*dv/dt The Attempt at a Solution I have...