Equivalent Definition and 1000 Threads

Hello all, I'm a new member. I've decided banging my forehead until its red will not make me any more able to solve my practice problems. I hope I haven't posted this in the wrong forum but here is the question in concern: Select R in the circuit so that VL= 5 V (see circuit in attachment...

I'm writing this on my iPhone. So, forgive me if the formatting isn't just write. 1) problem statement: here is the region of the integration of the integral: -1 to 1, x^2 to 1, 0 to 1-y dzdydx. Those bounds go from the outermost integral to the innermost. The problem asks to rewrite the...

Wikipedia says: second paragraph here: http://en.wikipedia.org/wiki/Dark_energy Vaccum energy (density) can vary over time and space? Is that accurate? I've read the cosmological constant can vary, but not vacuum energy.

If the 'average' intensity of direct sunlight on a warm summer day could be re-produced in a full spectrum light bulb, how many watts would that bulb be? I'm trying to find a bulb I can use to calibrate a photo sensor to sunlight intensity but my shop is on the base floor where there are no...

Please Help me out with this one. Can all patterns in 2D or 3D, have an equivalent equation in polynomial?

Homework Statement Find the equivalent resistance for the circuit in the figure. (Use the following as necessary: Vemf, R.) Homework Equations V=IR The Attempt at a Solution This problem isn't that hard, but I'm having trouble trying to visualize how to combine the resistors. The...

Okay I am wondering is there an equivalent to uploading pdfs online and just link it with the url like uploading images to imageshack? Does anyone know if such thing exists? Thank you

Prove that two norms ||.||1 and ||.||2 are equivalent if and only if there exist 2 constants c and k such that c*||x||1 <= ||x||2 <= k*||x||1 for all x in the concerned vector space V. Attempt-> Equivalence implies a ball in norm 1 admits a ball in norm 2 and vice versa. For normed linear...

Two metrics 'd' and 'f' are said to be equivalent on a metric space X, if they have the same set of open sets. This is equivalent to saying every open ball with respect to d contains an open ball with respect to f (different radius) and vice versa. (As every open set is a union of open balls)...

Homework Statement Find the equivalent capacitance of the infinite system between points a and b (see figure). Where Vi is the potential difference in the number i capacitor. Homework Equations Q=CV The Attempt at a Solution For number i capacitors we have the relations Q_i=CV_i...

Homework Statement I don't know where to start. Can anyone recommend a book the instructor didn't assign one.

The answer to my Kaplan test (studying for the DAT, just FYI) says 3, but I think it's 4? Am I wrong?

What is the equivalent capacitance of the network. Parallel: C1 + C2 + C3 + Cn = Ceq Series: 1/C1 + 1/C2 + 1/Cn = 1/Ceq I added C2 C3 C4 and C5 as parallel and then added this to C1 as a series.

Homework Statement Find the Thevening Equivalent Circuit for the following circuit: Homework Equations KVL, KCL. The Attempt at a Solution First of all, I calculate the current in the middle mesh, which I'll call i2: - j25 = ({i_2} - {i_1})(3 + j4) + {i_2}(10) where i1...

Homework Statement Find the equivalent resistance in the circuit below: Homework Equations The Attempt at a Solution I know the two 4 Ohm resistors (on the same wire) are in series and thus add to 8 Ohms. However, I do not know where to go from here. When the resistors are in a...

1. let's have 2011 point each pair connected by a resitor R. what is the equivalent resistor between each pair of points conneced by R? 2. due to the symmetry the equivalent resistor between two arbitrary point connected by R is always the same. let's take two of this contigouspoins. the...

The title basically says it all, here they are: \lim_{n\rightarrow\infty}a_n=a. And \lim_{n\rightarrow\infty}|a_n-a|<\varepsilon\hspace{7 mm} \forall\varepsilon>0

I have the following logical statement (A \wedge B) \Longleftrightarrow (A \wedge C) I want to find other logical statements that are equivalent to this. But I don't want to draw truth tables. Is there a list of 'theorems' that I can look up somewhere? For example, if I have an equivalent...

i am trying to find the short circuit current for the following circuit. the RL is the thevenin equivalent resistance. i am trying to find the current when RL is a wire (short circuit). by KVL, i have IR1 + \mu1(v2-v1) + IR2 + \mu2(v3-v1) + IR3 = 0 (the above is not formatted...

Dear forum, DOE and MEXT (Japanese Ministry of Education, Culture, Sports, Science and Technology) have pulished the results of common airborne measurements of the http://www.mext.go.jp/component/english/__icsFiles/afieldfile/2011/05/10/1304797_0506.pdf" inside the 80 km zone of Fukushima...

I need help finding the thevenin equivalent voltage for the following network: i did source transformations so that i could analyze it using the node voltage method. my equations are: I1 = v1 (a) vx + vx - vT = v1 + av1 - bv1 2vx - vT = v1 + av1 - bv1 (b) vT - vx + vT = bv1 2vT - vx = bv1...

Homework Statement A variable resistor (RL) is connected to an unknown circuit. It is found that the maximum power that can be dissipated in the resistor (RL) is 10W, and that this occurs when the value of the resistor (RL) is 25ohms. Derive the Thevenin equivalent circuit for the unknown...

Homework Statement Show that R \approx R+ , that is, the set of all real numbers is equivalent to the set of all positive real numbers Homework Equations The only relevant equation is finding one such that F:R\rightarrowR+ is a bijection. The Attempt at a Solution I've...

Hello everyone, I just mailed this question to NASA's Cosmicopia but I'm afraid they might not be able to reply. So I registered in these forums to see if maybe someone can give some guidance. So here it is: We know that accelerating a body with mass to the speed of light requires...

In a thevenin equivalent circuit are you able to find the power used in the circuit by the variable load? I have a circuit where the variable load is in parrallel I was thinking the power used in the original circuit by the variable load would be different than in the equivalent because it is...

Homework Statement For the circuit in the link below, find C equivalent: https://picasaweb.google.com/lh/photo/-p0vPLyvxZ_W_sXiWEIikDlT_BqmZyKP1qROOFyElOQ?feat=directlink Homework Equations The Attempt at a Solution I tired many ways to solve this but the middle branch...

Hi there, first, I apologize for my poor English. I made a simulation model and get results from HFSS Model has a equivalent circuit like that.(1) I run that model and get pair of solutions 'frequency vs response' like S parameter for each frequency. So, with these results, is it possible to...

hi :smile: I'm having some trouble figuring out the Thevenin equivalent for this circuit. As you can see, there are two dependent sources (current dependent current source & voltage dependent voltage source) and no independent source. I have started trying to analyse the circuit by...

Homework Statement For the capacitor circuit shown below: A. Find the equivalent capacitance B. What is the charge on the 3\muF capacitor? Homework Equations Q= C\DeltaV Parallel= C1 +C2+C3 Series= (1/C)=(1/C1)+(1/C2)+(1/C3) C1= 8\muF C2= 5\muF C3= 3\muF The Attempt at a...

I'm wondering of there is an open access archive of engineering topics, similar to ArXiv. Does anyone have any information?

The Problem I've been given the beam shown below to carry out the Hardy Cross method (Moment Distribution) too. I have no problems with the method but I'm struggling with part b, which states "Replace column by an equivalent force and couple at point C"...

Homework Statement http://img825.imageshack.us/img825/2306/theveninequiv.png I'm trying to find the Thevenin equivalent resistance for this circuit, but it's proving difficult. I'v tried to Zero all sources, (assuming that Zero'd current sources are open circuits), and i drew the...

I've made some capacitors association exercices and i got stuck on 2 of them. Q1: Q2: How can i get the equivalent capacitance on this 2 capacitors systems? Ty

for what values of C1, C2, and C3 make the terminal pairs equivalent? i know the 2f and 1f capacitance are in series: (1*2)/(1+2) = 2/3 and i know the 1/2 f is parallel to the preceding capacitors: 2/3 + 1/2 = 7/6 but i am unsure where to go from here... any help would be...

Homework Statement If each capacitor is filled with a dielectric material (with constant K, kappa), what is the new equivalent RC circuit? All resistors have equal value, and capacitors have equal value (without a dielectric), C. Homework Equations C = (Epsilon * Area) / Distance C with a...

Homework Statement [PLAIN]http://img593.imageshack.us/img593/6015/251a.png Homework Equations for combining resistors in series: R1 + R2 for combining resistors in parallels: R1R2/(R1 + R2) The Attempt at a Solution I've tried redrawing the circuit many times trying to make it easier to...

I have a washdown spec for a unit we are designing. We need to be able to withstand a maximum of 85 gpm through a 5/8" nozzle at 75gpm. Now, I don't have access to equipment that can mimic that scenario. What I'm wondering if can I use my average, run-of-the-mill, garden-variety pressure...

hello, I would like you to take a look at the picture below. My question is why it is states that de resulting moment vector is collineair with the force vector... This is my method to solve this kind of problems: *determine the moment about the three axis => than we now the 3...

I know this probably sounds weird, but I have a research problem that requires "random" analog circuits. Basically what this means is that I create Spice netlists by randomly adding linear and/or nonlinear components of random types with random node and parameter values. This works fine and I...

Is it possible to derive a formula for the equivalent resistance of n such sections in cascade? Show your analysis. Series: Reqv = R1 + R2 +...Rn Parallel: Reqv = 1/{(1/R1) + (1/R2) + (1/R3) +...(1/Rn)}

Homework Statement The question asks to find the Thevenin equivalent circuit as shown in the attachment. (It's a BJT problem, but I'm having difficulty with the first part). Homework Equations Where are terminal points I need to worry about when making it an open circuit? That's the biggest...

May anyone please help with the method of getting Thevenin Equivalent resistance (RTH) for the attached circuit. I have already found VTH to be 8V. Sim

Homework Statement All the wires on the front and the back hexagonal face (of the Skelton hexagonal prism) have resistance R. All the wires along the lines joining the vertices of two hexagons have resistance 2R. The equivalent resistance between P and Q as shown in the figure is The...

The question was to rank from highest to lowest equivalent resistance. This is what I came up with, but it was counted wrong and I don't understand why. http://i324.photobucket.com/albums/k327/ProtoGirlEXE/100_0687-1.jpg The equivalent resistance of resistors in series are added while in...

Given a crystal structure and the cell edges (a,b,c) , angles (alpha, beta, gamma) and the fractional coordinates of all atoms in the unit cell. Also given an arbitrary unoccupied site P by fractional coordinates (s1,s2,s3). How can I determine all the sites that are crystallographically...

Homework Statement Compare the function f(z) = (pi/sin(pi*z))^2 to the summation of g(z) = 1/(z-n)^2 for n ranging from negative infinity to infinity. Show that their difference is 1) pole-free, i.e. analytic 2) of period 1 3) bounded in the strip 0 < x < 1 Conclude that they are...

http://xkcd.com/356/ I'm clueless, yet curious.

Homework Statement Find the input impedance Z. (i.e. Find Z equivalent.) Answer in the back of the book: Z=84.907-j20.12 ohms [PLAIN]http://img834.imageshack.us/img834/8508/circuit.png Homework Equations n/a ** j=sqrt(-1) The Attempt at a Solution I combined the 60-ohm, 50-ohm, and...

The TL431 is a widely used as reference for voltage regulation. But in some cases there is a R and a C in the TL431 loop. I googled for the euivalent diagram, its an opamp with a reference and a diode in the feedback loop(+ve terminal of opamp and Cathode). I don't understand the function of...

Homework Statement Calculate the equivalent resistance between the points X1 and X2. Homework Equations R series = sum of resistances R parallel = reciprocal of resistances The Attempt at a Solution I'm sorry I do not get any idea on solving the question. I have done it in the...