Equivalent Definition and 1000 Threads

I was thinking about this when I was trying to work out a simpler way of finding the volume of a sphere. Suppose we cover a hemisphere with a piece of pliable thin cover. Stretching the cover flat would make a circle. The circumference of the sphere is 2*pi*r. The distance along the surface of...

Homework Statement Find the equivalent resistance of: https://www.circuitlab.com/circuit/5s3ebn/screenshot/1024x768/ Homework Equations The Attempt at a Solution I've simplified it a bit already... Just very confused in regards to which resistances are in parallel since they...

Homework Statement Find the equivalent resistance of the following circuit. http://img706.imageshack.us/img706/9644/zkz7.png Homework Equations none The Attempt at a Solution I am not able to find out which are resistors are in series and are in parallel.Is there any special...

A is orthogonal if the A^{-1} = A^{T}. Thus, AA^{T} = I. However, is the statement A is orthogonal equivalent to A^{2}=I. I don't think the statements are equivalent, but it comes from a test. Thus, I'd hope the test is correct.

This is an odd question. I was talking with a social scientist the other day and he seemed to think that the amount of energy it takes to raise the temperature 1 degree Celsius or Kelvin was minutely different depending on the temperature (ie near absolute zero the energy it takes to increase T...

On my studying material I noticed that for "devices in parallel" problems, a question of the type "Find the probability the device works for 1 year" is dealt with P(A or B) where P(A), P(B) are the probabilities of each of the instruments working for one year, which is something I intuitively...

Homework Statement \mathbf{D1:}\forall\varepsilon>0,\exists K\epsilon\mathbb{N},\forall n\epsilon\mathbb{N},n\geq K\Longrightarrow|x_{n}-x|<\varepsilon \mathbf{D2:}\forall\rho>0,\exists M\epsilon\mathbb{N},\forall n\epsilon\mathbb{N},n>M\Longrightarrow|x_{n}-x|\leq\rho Show these two...

Homework Statement Showthe two forms of the sample variance are equivalent: \frac{1}{n-1}\sum_{i=1}^\n (Yi-Ybar)2 = \frac{1}{n(n-1)}\sum_{i=1}^\n \sum_{j>i}\n (Yi-Yj)2 The first summation is from i=1 to n, the second is i=1 to n and the third is j>i to n. Sorry, I don't know how to format...

How are the circuits (a) and (b) equivalent? i0 is the sum of two currents that flow from high to low potential (flow of positive charge) So why does i0 not flow from high to low pot?

Homework Statement Find the equivalent resistance between terminals a and b Homework Equations Series: Req = summation of resistors Parallel 1/Req = summation of 1/resistances The Attempt at a Solution So I figured out the easy ones, and so I'm here at the moment...

Homework Statement Show that sin(\alpha)-sin(\beta)=-\frac{v}{c}sin(\alpha+\beta) is equivalent to cos(\beta)=\frac{-2\frac{v}{c}+(1+\frac{v^2}{c^2})cos(\alpha)}{1-2\frac{v}{c}cos(\alpha)+\frac{v^2}{c^2}} Homework Equations This is the last step in the derivation of the...

Homework Statement If R1 = 2 Ω, X1 = 1 Ω, R2 = 2 Ω, and X2 = -2 Ω , the equivalent impedance Zeq (in ohms) at terminals a and b is: (the circuit diagram is attached to this post) a. 3 + j 0 b. 3 + j 2 c. 3 - j 2 d. 0 - j 2 e. 0 + j 2 The answer is a. I have no idea how to...

Homework Statement Find the Thévenin equivalent of the circuit shown in FIGURE 1. Homework Equations Any two-terminal network can be replaced by an equivalent circuit consisting of a voltage source and a series resistance equal to the internal resistance seen looking into the two...

Hello I have to check if the following relation is an equivalence relation. \[m\sim n \;\;\mbox{in}\;\;\mathbb{Z}\;\;\mbox{if}\; mn > 0\] I think this relation fails to be reflexive since $(0,0)$ does not belong to this relation. Hence this is not an equivalent relation. Is this ok ? Thanks

This is the equivalent circuit to a transistor, I am to find: i )Short-circuit input impedance, H11 ii )Open-circuit reverse voltage gain, H12 iii)Forward current gain, H21 iv)Open-circuit output admittance, H22 Homework Equations Vin = (H11)(Iin) + (H12)(Vout) Iout = (H21)(Iin) +...

Let Z:= A^T, where T is a countable set and A is a finite set. Under the product topology, Z is a compact metrizable space. (As a special case, notice that Z could be the Cantor set). Given a closed set X \subseteq Z, I'm interested in answering the question, "Does there exist some partition...

Homework Statement Prove that the equivalent resistance in a parallel circuit with 2 resistors with resistance R1 and R2 is always lesser than the resistance of either resistor. Homework Equations Rt= (R1 x R2)/(R1 + R2) The Attempt at a Solution I tried starting from R1 + R2...

Is there a way to express ##{n\choose k}{n\choose r}## in another form without n as the "top" of the binomial coefficient? I remember seeing it once but I forgot what it was.

Homework Statement I attached a picture of the molecule. My question is why are the methyl group at the top not chemically equivalent. The answer says that this molecule makes three singlets in HNMR but I was thinking it should make only 2 because the top methyl groups are chemically...

Homework Statement Apply source transformation to find the Thevenin equivalent circuit Homework Equations voltage division, source transformationThe Attempt at a Solution Simplify the far left current source to get Then Vth of this = (50V + 20V)*(100/200) = 35V and Rth of it = 100||100 =...

Homework Statement Homework Equations Leq = L1 + L2 + ... + Ln (series) Leq = 1/((1/L1) + (1/L2) + ... + (1/Ln)) (parallel) The Attempt at a Solution For part A, I redrew the circuit (above), taking into account that the switch was open, but I'm not entirely certain I did it...

Homework Statement Prove that the two trig identities are equivalent. cos \ x \ -\frac{cos \ x}{1-tan \ x} \ = \ \frac{sin \ x \ cos \ x \ }{sin \ x \ - \ cos \ x} The Attempt at a Solution My professor recommended that we only work with one side of the equality when we're trying...

Homework Statement Calculate the total equivalent resistance between A and D - ( All resistors are 1 ohm ) Homework Equations - The Attempt at a Solution The only thing I can see is that the two straight 1 ohm resistors are in parallel , giving 1*1/1+1= 1/2 resistance. But what...

Homework Statement Calculate equivalent resistor The Attempt at a Solution Req=(10 series 5)//(10)//(3)//(2)//(9 series 40) series 8//(4) I am not sure in the bolded text, is 9Ω connected serially with 40Ω.

I know that this is basic, but I don't get it. Say we have the system, x + y = 32 3x + 2y = 70 Each equation represents a graph, and the solution is the point where the two lines intersect. Here is where I am confused: x + y = 32 2x + 2y = 64 What is the proof that the two equations...

It is the procedure you do to get ground term symbol in LS coupling. What is meant by this "ground term"? As in a physical meaning. If you don't know the procedure it is in this link: http://en.m.wikipedia.org/wiki/Term_symbol, please seek "Ground State Term Symbol" Section.

Homework Statement Use source transformation to find the Thevenin equivalent circuit with respect to terminals, a, b. Homework Equations Voltage Division: (V in)*(R1/R1+R2) Thevenin / Norton / source transformation procedures RTh = RNo VTh = INo*RNo Polar...

Hey guys, How come a representation \rho of a group G is always equivalent to a unitary representation of G on some (inner product) space V ? Can anyone provide a good source (book, preferably) which states a proof? Thanks

Homework Statement Find Vt and In Homework Equations KCL The Attempt at a Solution I found Rt to be 5.94 ohms (1/(1/7+1/9)+2) Then I am stuck. I know to find Vt (which is equal to Vopen circuit), I have to do a KCL in an open circuit, so my KCL equation is 2+Voc/3=Voc/4 So...

Equivalent weight of sulfur in SCl2 is 16,what is the equivalent weight of S in S2Cl2? [S=32,Cl=35.5] I know that the answer is 32. But how how can the equivalent weight of Sulfur be 32? We know that equivalent weight=atomic weight/valency Now sulfur has variable valency of 2,4,6 .So the...

What is the equivalent weight of ozone molecule? I mean how can I find out the equivalent weight of molecules? Is it same as the equivalent weight of element? For example, FeCl3 ,what will be the equivalent weight of chlorine ?

Homework Statement Can you check if the values and labels are correct Homework Equations The Attempt at a Solution

Homework Statement Determine the equivalent impedance of the following network: (My bad, the element at the far right where the j2ohm is was supposed to be an inductor, fixed now. The numbers are correct too.) Homework Equations R(series) = R1 + R2? R(parallel) = [ (1/R1) + (1/R2) ]-1...

My teacher, textbook and the internet have differing definitions. First of all: Equivalent. My teacher says that two parallel vectors with the same magnitude are equivalent, but my textbook says that two vectors in the same direction are equivalent. ×--> <--× are these equivalent?And...

Homework Statement A scheme of springs and dampers is given. What is equivalent stiffness and damping? Homework Equations For stiffness in series: keq=ka*kb/(ka+kb) For stiffness in parallel: keq=ka+kb For dampers similarly. The Attempt at a Solution To me it looks like k1 and k2 are in...

Hi, if a load is given in MVA and I work out the Real and reactive power, is the equivalent complex impedance per phase the values of real and reactive power divided by three in the following form: Z (per phase) = Real power/3 + j Reactive power/3 Im not sure how to work out whether the...

What is the equivalent capcitance of this circuit! -- Figured it out. I have a Physics final exam in 2 hours and I'm re-reviewing things... This problem DOESN'T make any sense! 17. If C1 = 2 F, C2 = 3 F, C3 = 5 F, C4 = 6 F, the equivalent capacitance of the circuit is: A. 8.5 F is supposed...

Homework Statement Given the circuit (Attached in image) Find the thevenin equivalent circuit. I know its a fairly simple thing, But I am not understanding where the lecturer is getting this answer from, unfortunately his solutions just state the voltage so I feel like I must be missing...

1.Is sensible heat involved in the equivalent evaporation of boiler? While studying about the equivalent evaporation of boiler I got confused about the equation. The equation says,2. E=Total heat required to evaporate feed water/2257(latent heat of water) The definition of E is the amount of...

Homework Statement Consider the circuit which consists of two ideal inductors L_{S} ,L_{P}. These inductors are magnetically coupled with mutual inductance, M. It is possible to replace these magnetically coupled coils by three coils which do not share magnetic flux linkages. The two...

Hello, I have to prepare a Methylene Blue solution 1ml = 0.01 meq, or 0.01 N, from MB powder. To know the amount of powder required, I need to know MB's equivalent weight, or equivalent number, but haven't been able to find it so far. Does anyone know? Help appreciated

Homework Statement Hey, I've always had problems with circuits and finding out equivalent resistors, and identifyuing which are in parallel, and which are not Homework Equations I need help with the circuit attached. Can someone clear this problem with circuits once and for all. PS: I...

Homework Statement determine thevenin equivalent of circuit at terminals (a,b): Homework Equations Z(L)=jwL Z(C)=-j/wC V(th)=V(oc) R(th)=V(ex)/I(ex) The Attempt at a Solution actually 1st i need help with finding V(th). i do know that V(th) would be the voltage across the 2ohm resistor, so...

Homework Statement Draw the equivalent circuit for a lumped capacitance with dielectric losses that would be appropriate at RF frequencies. Homework Equations Possibly Xc=-j/ωC The Attempt at a Solution I do not really know what the question is asking. I know that a lumped capacitance...

I understand that in GR mass is considered a distorting of space-time. If you had a teleporter which transmitted an object's energy perfectly as photons to be reconfigured at a perfect reciever at the destination location, whilst in transit as a (very high energy) light pulse, would the same...

Homework Statement Homework Equations w = 10^5 rad/s Z(L)= jwL Z(C) = -j/wC Z(eq)= ?? Zeq(rectangular form) = a+jb Zeq(polar form)= p<(theta) p = sqrt(a^2 + b^2) theta = arctan(b/a) The Attempt at a Solution i calculated the impedences across the inductor/resistors: across 0.5uF capacitor...

when i short the batteries to find the rth, i can't get whether is should put delta to star transformation to find thevenines resistance? can some one tell me how to calculate thevenines equivalent resistance in the figure shown... step by step

Homework Statement Please take a look at the attachment to see the circuit. My question is how do I find the equivalent resistance of this circuit? I have done the other two parts but this part has got me stumped. I also drew my currents on the picture. Homework Equations The...

I was hoping someone could help me understand the equivalence between the definitions for functions to be continuous between topological spaces, ie: For X and Y topological spaces, and f:X-->Y a function, my notes don't prove why these definitions are equivalent (possibly because I'm missing...

Homework Statement For t<0, the circuit shown below with the voltage source at 11 volts and three resistors combined into an equivalent, Req. We need to find the Thevenin equivalent circuit for the part of the circuit connected to the inductor. First find Req, by combining series and...