# circuits

1. ### PWM and it`s duration (picosecond pulse widths)

Hello, I wanted to ask, if anyone knows of a realistic circuit, which could be capable of producing a PWM of 1 pico second on and 350 ps off. Thanks to everyone taking the time to answer in advance.
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### Engineering Simulation of Circuits Without Kirchhoff's Laws?

1. The problem statement, all variables, and given/known data I am currently drafting a proposal for a project in Computational Physics. I'm planning on creating a program that simulates circuits numerically instead of solving the system of equations. The purpose of my project is to observe the...
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### Checking my answer... finding the power of a current and a voltage source

1. Homework Statement The current source and voltage source in the circuit shown in the Figure below are connected in parallel so that they both have the same voltage, vs. The current source and voltage source are also connected in series so that they both have the same current, is. Suppose...
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### Resistance in circuits

1. Homework Statement 1) what is the total resistance of this circuit between points A and B? 2) if the horizontal resistor was replaced with an ammeter what would it read if a 6V battery was placed between points A and B? let R = 20 ohms 2. Homework Equations 3. The Attempt at a...
5. ### Engineering DC circuit analysis: conceptual mistake?

1. Homework Statement 2. Homework Equations I have a circuit that consists on 3 components in parallel: a current source Ia, a resistor R and a capacitor C. Ia is directed upwards, while the currents through the capacitor and the resistor are both directed downwards. Select the correct option...
6. ### Engineering Open-circuit voltage in Thévenin equivalent

1. Homework Statement Determine the Thévenin equivalent of the following circuit with respect to terminals A-B 2. Homework Equations $$U=RI$$ The sum of the currents in a node is zero. The sum of voltages in a mesh is zero. I'm always considering the currents in the resistors directed...
7. ### The validity of the interconnection of ideal sources

1. Homework Statement Sorry in advance for such a basic question, just starting my first electrical engineering course. The question asks if the interconnection of ideal sources is valid. The next part of the question asks us to verify that the total power developed in the circuit equals the...
8. ### Engineering Voltages and current in a circuit: incorrect signal?

1. Homework Statement Consider the circuit in the figure and calculate V1, V2 and IA. Notice that the symbols V and A represent, respectively, an ideal voltmeter and an ideal ammeter. 2. Homework Equations Ohm's Law $$V=RI$$ KVL The sum of the voltages of a mesh in a circuit equals zero...
9. ### Electric cars -- Does periodic coasting help efficiency?

Hi. I'm a student of electrical engineering, and I've always been interested in the idea of electrical cars, so I came up with a question: let's suppose we want to have a normal trip with car, and then we're not interested in going so fast with it. When we are driving in this condition, it isn't...
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### D-flip-flop circuit

So I have been watching his videos trying to get ready for second year engineering (electrical). However, I am very confused as to what exactly is going on when he is pressing the enable/pulse switch during the run-through at 14:45. He has the enable connected to a capacitor, and he calculates...
11. ### Will there be a difference between the readings of V1 and V2

I= Current flowing V1= Voltmeter 1 V2= Voltmeter 2 My question is that if there would be any difference between the readings of V1 and V2? We know that: By Ohm's law: V= I.R also: Combined resistance of R1 and R2 will be: 1/RCombined Resistance of R1 and R2= 1/R1+1/R2 The reading in V2...
12. ### How would you solve the following cuircut problem?

1. Homework Statement You are tasked with designing an electrical circuit with a motor, a battery, and several 1ohm and 2ohm resistors. The motor is designed to run at a current of 20A and a voltage of 10V, but your battery supplies 15 V. The motor can then lift a 4kg mass 2.25 meters in...
13. ### Final charge on capacitor for an RC circuit

1. Homework Statement 2. Homework Equations $q = CE(1 - e^{-t/RC})$ 3. The Attempt at a Solution I assumed that, since the problem specifies that sufficient time has passed, it meant to say that enough time passed. thus making the exponential term in the equation go down to 0, and the...
14. ### The voltage across an AC source and a resistance in series

1. Homework Statement In the circuit below, the RMS of the AC source is 100V, the inductive reactance is 50 ohm, the capacitive reactance is 200 ohm, the resistance is 40 ohm and the current flows in the circuit is 0.644 A. Determine the reading of the voltmeter. 2. Homework Equations 3...
15. ### Error message in PSpice

1. Homework Statement Run a transient simulation and plot the three outputs, Vo(t), on the same plot. Use the following settings: 1. Set the Run Time (or Stop Time) so that you plot 3 cycles of Vo(t). 2. Set the Maximum Step Size so that you get at least 100 points per period for Vo(t). 3. Set...
16. ### (LC Circuit) Finding cap charge after connecting to inductor

1. Homework Statement A capacitor with a capacitance of C = 5.95×10−5 F is charged by connecting it to a 12.0 −V battery. The capacitor is then disconnected from the battery and connected across an inductor with an inductance of L = 1.50 H . What is the charge on the capacitor after a time...
17. ### Why does this bulb get brighter after the switch is closed

1. Homework Statement 2. Homework Equations None 3. The Attempt at a Solution The answer is B, bulb B will be brighter than before. My thought was that initially, the current gets split so that 2/3 I0 goes to the branch with 2 bulbs, since it has twice the resistance of the first branch...
18. ### Potential difference between two points

1. Homework Statement Question from OCR A Level Physics Exam 2014 (i) and (ii) = definitions (iii) = explanation (iv) = P.d. at 6Ohm Resistor = 0.48V (v) Suggest why the p.d. between X and Z is zero 2. Homework Equations I don't think there are any 3. The Attempt at a Solution I...
19. ### Why do the capacitors in this circuit have the same voltage?

1. Homework Statement 2. Homework Equations C = Q/V 3. The Attempt at a Solution I understand that capacitors in parallel have the same voltage, but wouldn't they be in series after the switch is flipped, since no current goes to the left most portion of the circuit.
20. ### What happens to a coil of wire as current is increased?

1. Homework Statement 2. Homework Equations L = (N * F_b) / I (where F_b is the magnetic flux) emf = -L * (dI/dt) 3. The Attempt at a Solution I originally thought that the inductance would decrease since it is inversely proportional to current. But, looking at the equation for emf...
21. ### Simple inductance question: Finding steady state current

1. Homework Statement 2. Homework Equations I = E / R_total 3. The Attempt at a Solution I mostly just want to clarify that my thinking is correct. The solution for this problem shows that the current is split evenly between the two paths. Is that because we're assuming that the inductor...
22. ### I Help in understanding a quantum circuit

I'm in a proyect to simulate quantum circuits in robots like in this paper ( http://ieeexplore.ieee.org/document/4215941/ ) ,the first thing that i need to do is to simulated the circuit that is in that paper: But i'm having trouble understanding how the hadamard gate affects the "C"...
23. ### Diode - Resistor Combination

Helo, I am in an electronic course and we just started studying diodes. I am stuck on the following problem: Place a 100 ohm resistance in series with a diode, and plot current versus voltage across the series combination. I am also given the following values for the diode: n = 1, Is =...
24. ### Tiny Tweak in Teaching Basic Circuits

I'm sure we have all seen the frequent questions from students who don't understand the difference between potential and voltage in a circuit. They seem to think that zero voltage has physical significance. Even using the phrase "voltage drop" is not suffienct, because they say, "What happens...
25. ### Circuit with two voltage sources, finding voltage at nodes

Okay, so why is it that Vc assumed to be 12v - 0.7v (D1), how about contribution from the 9v battery?? Why is this not affecting the voltage at node C? Why Vc isn't 9v - 0.7v (D2) = 8.3v?
26. ### Summing op amp circuit help?

1. Homework Statement Solving for this circuit here, where V = -5V 2. Homework Equations 3. The Attempt at a Solution I found the equation for a summing op amp like this one, plugged everything in and ended up with -3V, which is marked wrong. I'm really at my wit's end here and the...
27. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

1. Homework Statement 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. 2. Homework Equations V = IR V = V0exp(-t/tau) 3. The Attempt at a Solution I am trying to find the...
28. ### The current in RLC circuit.

1. Homework Statement In the tuned circuit below, what will happen to the reading of the ammeter when: a) source frequency increases. The voltage is constant b) the capacitance increases. The voltage and source frequency are constant c) The voltage increases. Source frequency is constant...
29. ### Current Through A Resistor That Is In Parallel With A Capacitor

1. Homework Statement My question is regarding part C of the question. 2. Homework Equations V = IR V(t) = V(1-e^(-t/tau)) 3. The Attempt at a Solution My idea is to use Kirchoff's Voltage Law and find the voltage of the capacitor as a function of time, then since the voltage across...
30. ### Electrical Circuit Problem / Electric Potential Difference

1. Homework Statement In the following picture, the absolute value of the difference in electric potential, between points A and B is: A)5V B)4V C)3V D)1V E)0V 2. Homework Equations E =qV V = iR 3. The Attempt at a Solution I have no idea where to start on this one, just started my...