Electric circuit Definition and 199 Threads

1) I don't understand why current flows, for example when you have a source, it has 2 poles, + and -: then the electron should go towards +, if it's in the position 'D', it should just be stuck -- my theory is that because the electron that's in 'A' "enters the battery", so the battery has...

Is asking for the voltage of a point in a wire (before/after a resister) the same as asking for the voltage across that resister? I understand voltage is relative.. Here is the circuit: I can't wrap my head around what V1 represents. Other questions in this assignment specifically ask...

Homework Statement From this circuit diagram assume Vs and R1 through R2 are known. Find the following: a) How many unknown currents are there? b) How many independent equations can be written using KCL? c) How many independent equations can be derived from KVL equations...

Homework Statement I'm supposed to find the missing resistances, currents, and voltages from the first picture (attached)Homework Equations v = IR R = V/I I=V/RThe Attempt at a Solution My attempt is in the second attached picture. I'm completely lost on what to do for R3. Would R3 and R4 have...

Hi I need a good book for circuit analysis (preferably, it should be available on my cell phone via, for instance, Kindle or Aldiko.. Or PDF). My curriculum includes AC and DC circuits with: Resistors Capacitors Inductors BJTs Diodes FETs (JFET and MOSFET) Opamps I have to be able...

Hello friends, I have problems in simplifying electrical circuits. I've attached 2 (of the many) questions I have trouble with. According to the question, superposition must be used to solve these. In the first question, supposing the voltage source doesn't exist, how do you simplify the left...

Hi. So we all know that electricity requires a complete circuit in order for electrons to flow in a wire. It's my understanding that this is due to the charge differential at the positive and negative, creating an electric potential. So, given that (or correct me if my understanding is wrong)...

1. The diagram attached shows part of an electric circuit. What is the current through resistor R1? To summarize: I=6.0 A R1 = 11.0 Ω R2 = 33.0 Ω R3 = 67.0 Ω R2 and R3 are in parallel, and R1 and R2 and 3 are in parallel. I know we aren't supposed to attach pictures of questions...

1. A battery whose emf is 6.0 V is connected to a 2.0 Ω resistor. The voltage drop across the 2.0 Ω resistor is 5.0 V. What is its internal resistance? a) 0.40 Ω b) 1.7 Ω c) 2.4 Ω d) 2.5 Ω Homework Equations VT=ε-Ir The Attempt at a Solution I know that ε=6.0 V VT=5.0 V...

Homework Statement 1. The diagram shows a simple circuit. Which statement is correct? a. When switch S is closed, the potential difference across the battery falls because work is done against the internal resistance of the battery b. When switch S is closed, the potential difference...

We have the circuit that I have attached in the figure.I have to find i1 i2 and V. SO I firt find i1. I find the equivalent resistance ( I am not writing it all here because it takes too long) and Re=10 Ohm.So i1 =V/Re=10 A. I thought that to find i2 and V I had to use the current division...

Homework Statement A 45 kg object is lifted vertically at a constant speed to a height of 9.0m by a 750 W electric motor. If this motor is 25% efficient in converting electric energy to mechanical energy, how long does the motor take to lift the object? Homework Equations The...

Homework Statement A battery has an emf of 24 V and an internal resistance of 0.25 ohm is being charged at a rate of 24 A. What is the voltage required to do this? Homework Equations V(terminal) = emf +/- Ir The Attempt at a Solution Since the battery is getting charged that...

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...

Homework Statement Attached diagram. The resistors don't have any concrete resistances. Need to express the total resistance of the part of the circuit shown in the picture. Homework Equations Series - R= ƩRn Parallel - R = (ƩRn-1)-1 The Attempt at a Solution R1 and R2 make a series...

Homework Statement Design a dc circuit utilizing a 15V voltage battery to provide the following node voltages: +10V, +5V, and -5V w.r.t. a circuit ground node. Select your resistors such that the maximum power demand on the battery does not exceed 1mA. The attempt at a solution I've...

Homework Statement Please see the picture below. http://img23.imageshack.us/img23/2505/capturecfk.png The title of this section of my lab is "Voltage divider". Now I have taken this class before =(. But anyways I know that there is a whole voltage divider formula for resistors in...

Homework Statement http://img26.imageshack.us/img26/7307/captureghl.png I have a square that is 5 cm by 5 cm. I have filled it in with graphite from a pencil. The top left corner I have labeled A. The top right corner B. The bottom right hand corner C. The bottom left hand corner D...

Once again, my textbook seems to do a poor job of explaining another concept just like I commented earlier here. Anyways, here is the relevant part of the textbook: http://www.mediafire.com/view/?cw5t2wr9vqqprnv To calculate p4 in example 1.7, voltage of 8V is multiplied by a current of -0.2I...

My textbook does a very poor job of explaining how to assign signs to power: http://www.mediafire.com/view/?e0xr8j41tokujx6 It goes on to explain passive sign convention but it never explains active sign convention. Also, shouldn't the sign for power depend on voltage and current since power is...

Homework Statement The filament of the lamp in X breaks and the lamp no longer conducts. It is observed that the voltmeter reading decreased and the lamp Y glows more brightly. a) Explain without calculation why the voltmeter reading decreases. b) Explain without calculation why the lamp Y...

Hi all, I found the following equations for the electric circuit shown Vc(t) = - 1/(R2*C) * Vc(t) – 1/C * i(t) --------------------1 Vt(t) = Vc(t) – R1*i(t) ------------------------------------ 2 I have the following questions 1.The first equation should be dVc(t)/dt = -1/(R2*C) *...

Algebra mistake? The answer is11.8ohm for (a). Thank you!

electric circuit -- Why is the switch needed in this capacitor circuit? Hi, I have two questions with respect to the picture in the attachment.: 1) I have read, that the capacitor become charged, when the switch is closed. All right, but why the capacitor doesn't became charged before...

Homework Statement An RC circuit is given with a 1μF capacitor, a 25kΩ resistor and a 4μF capacitor, all in series. Initially, the 1μF capacitor has a voltage of 40V, while the 4μF capacitor has a voltage of 0V. The circuit, starting from the left and going clockwise is, 1μF (reverse...

Question is in paint doc... question c and d are what I am interested in... For both questions I used P=IV, this gave me a correct answer for d but not c. For c I got 9/2 the answer is 4.3. Is that close enough? Or am I using the wrong equation?

Homework Statement I have this circuit here.. http://s1167.photobucket.com/albums/q639/jay9313/?action=view&current=EM.jpg The question says that when switch S is open in the circuit shown above, the potential difference between points a and b would be.. A) 0V B) 6V C) 12V D) 24V E) 36V...

What does the slope of a length vs. resistance graph tell you? Slope=? What does the slope of an inverse resistance vs. current graph tell you? Slope=? __________________________________________________________________ Here's what I had to do for my lab: 1: Construct a circuit...

Hi I am having trouble figuring out what to do with negative reference voltages in my circuit. I attached my problem(Problem 3) and I know that some current will be drawn out of the ground and I think all of the diodes will be on but I am unsure how to approach this problem.

I have 2 questions 1st: How does the resistance decrease Current? (Apart from converting the electrical Energy into other forms of energy) 2nd: Why is the presence of Resistance felt in the entire circuit i.e. Current reduced in the entire circuit? Suppose there is a circuit with a cell...

Homework Statement A distant telephone, whose resistance is 300 ohms, is connected to the exchange 10km away by a pair of wires whose resistance singly is 50 ohms/km. A twig falls across the wires at a certain point producing the effect of a resistance, R, between the wires at that point...

Homework Statement For 1 and 2 : Find the equivalent resistance for the resistor network provided Homework Equations For resistor in series : Req = R_{1}+R_{2}+...R_{n} For resistors in parallel : Req = (1/R_{1}+1/R_{2}+... 1/R_{n})^{-1} The Attempt at a Solution For...

Homework Statement An electric circuit consists of a resistor with a resistance of 12 ohms, a capacitor with a capacitance of 0:1 farads and an inductor with an inductance of 2 henry connected in series with a voltage source of 52 cos t volts. Initially the charge on the capacitor is 3...

I just have a quick question. Are all three resistors in the figure below in parallel? I know that R2 and R3 are parallel to each other, but what about R1? [PLAIN]http://img189.imageshack.us/img189/4171/circuitzu.png

Hello, This is a problem that is buzzing me around for quite sometime since I took fundamental physics course. Consider an electric circuit with one battery and one resistor. And ignore the internal resistance of the battery and the resistance of the wires. 1) Does battery supply...

Homework Statement Homework Equations V=IR ? The Attempt at a Solution My main problem with this question is that impedance seems to apply only when inductors and capacitors are involved, but this circuit includes only resistors, so it seems to me like I could just treat it as resistance...

Homework Statement With respect to the attached drawing of an open circuit, which statement/s is/are true? A) The circuit is open therefor no current flows in it B) Vab = 0 C) Vab strives to infinity D) Kirchhoff's current law does not apply on an open circuit E) Vab = 20V F) The...

I just have a general question on rearranging circuits. Is there are certain rule that dictates how and when you can rearrange circuits? For example, in the diagram below, is the left circuit equal to the right circuit? And how would I know that?

Hello, I hope I can have some help for calculating the power of an electric circuit. Here is my query: I know that if I have for example 7 sources of energy and I connect them parallel then the end result would be that U=U1+U2+U3+U4+U5+U6+U7. And if I connect them consecutively then...

Homework Statement If I post this question in the wrong section please forgive me and direct me to the correct place. I want to ask about how electric circuit works. Let's use a basic circuit, which has a battery, wire, and resistor, for the problem. From what I learned, the electrons move...

Hi. I seek your opinions on a "simple" circuit: -------------------------- |........|...| Voltage..... Bulb2...Bulb3 |.......|...| |....Bulb1... | Here one have a voltage (battery) and three bulbs: Bulb1, Bulb2, Bulb3. We think of the bulbs as Ohm-resistances where Bulb1 is a series...

Homework Statement Find the voltage v across the 5 Ohm resistor as shown in the attached drawing. Homework Equations Ohm's law, V=IR The Attempt at a Solution I have done plenty of these using different techniques, superposition/source transformation, nodal or mesh analysis, etc...

So, I've had an argument with a friend of mine about how electrons behave in an electric circuit. He doesn't even know what quantum physics is and I have yet to explain it to him, but the question I'm asking my self is this: Let's say we have an electrical circuit similar to this one...

First of all, thank you taking a look at this. I hope to return to community in the future as I got help today. I'm assuming this belongs to introductory physics, so I'll post here, feel free to move if I posted in wrong section. Homework Statement A carbon wire and a Nichrome wire are...

Homework Statement Two light bulbs are rated as 60 W and 75 W at 220 V. If these are connected in series to a source of 220 V, what will the power in each be? Assume a constant resistance for the light bulbs. Homework Equations W=VQ P=IV V=IR The Attempt at a Solution I was...

Homework Statement http://img19.imageshack.us/img19/7701/screenshot20100808at010.png Homework Equations The Attempt at a Solution Do add up the resistances like this: R_{total} = (\frac{1}{R} + \frac{1}{r} + \frac{1}{r})^{-1} or R_{total} = R + (\frac{1}{r} + \frac{1}{r})^{-1}

Homework Statement When connected in series to a 110-V line, two resistors use one-fourth the power that is used when they are connected in parallel. If one resistor is 2.0 kΩ, what is the resistance of the other? Homework Equations 1/Rt = 1/R1 +1/R2 (total resistance in parallel)...

Homework Statement Electric circuit (as shown in the picture), is made from five elements. Failures of elements are independent, with probabilites: A_1-0.6, B_1-0.4, B_2-0.7, B_3-0.9 and A_2-0.5. Find the probabilty of current break, between M and N. Homework Equations For...

Homework Statement Three resistors and two batteries are connected as shown in the figure. The magnitude and direction of the currents in the unknown resistor "R" at the right and the 6.0 ohm resistor on the left are shown in the figure. The current in the 4.0 ohm resistance flows from B to...