Resistor Definition and 894 Threads

In an L-R-C circuit, if the reactance of the capacitor equals that of the inductor, X_L = X_C, and consequently the current is at it's max and we have resonance, will the temperature in a resistor with a positive temperature coefficient increase faster in this situation, and thus get increasing...

Homework Statement If possible, find reasons why the resistance of a resistor may have a different value when measured with a sine wave signal (a.c.) than when measured with a d.c. (dirrect current) source. Homework Equations The Attempt at a Solution Please correct me if anything...

Homework Statement When a 2-kΩ load is connected to the terminals A–B of the network in the figure, the current through the load is IL = 10 mA. If a 10-kΩ load is connected to the terminals, IL = 6 mA. Find IL if a 20-kΩ load is connected to the terminals. 2. The attempt at a solution I...

Hi all, I am studying to be an electrical engineer and I have a C programming course that all of a sudden took a massive jump..last week we were writing single For statements and things of that manner and now he assigned a program that's just got my completely stumped, I thought I was...

hello Find the power dissipated in the (6 ohm) resistor. the circuit is in the attachments i know that P in the resistor = (i^2)*R but how can i find the current in that 6 ohm resistor? thanks

Homework Statement the actual question is the resitivity of tungsten metal is 4.9x10to the power of -6 Ωcm. choose appropriate values for length and cross-sectional area for a home made wire resistor of resitstance 20Ω Homework Equations r=pl/a r-resistance a-cross sectional area in...

I was with my electrician friend the other day, and we stuck two copper wires into each of the holes of a regular 120V outlet then smashed a 100W light bulb and took the resistor (small coiled looking thing) out of it and set it on a piece of wood and touched the copper wires to each end of the...

Homework Statement I have three questions 1. How do you find AC voltage across resistor when there are both AC and DC current? 2. is AC voltage across a resistor different from voltage across a resistor? 3. Find AC voltage across Resistor (in this image) http://img199.imageshack.us/i/acv.gif/...

I have attached image. Thanks in advance.

Homework Statement For the RC Circuit (R = 100 Ohm, C = 100 Micro Farads, and an open switch at t=0), we know that the capacitor is charged to a voltage of 10 V prior to T=0. Find expressions for Vc(t) and Vr(t). Homework Equations Vc(t) = Vi * e(-t/rc)The Attempt at a Solution Vc(t) =...

Homework Statement The voltmeter shown in the figure below can be modeled as an ideal voltmeter (a voltmeter that has an infinite internal resistance) in parallel with a 11.0-MΩ resistor. Calculate the reading on the voltmeter for the following. R = 1.1 MΩ R = 10.8 MΩ R...

So i have a general question that I came across with source transformations, but this question can be classed as a beginner question. When I find the equivalent resistance, how do you determine whether or not it is in series or parallel with a source?

The meter in the circuit shown in the image has an uncalibrated linear scale. With the circuit as shown, the scale reading is 20. Find the scale reading when another 2000Ω resistor is connected across XY.

Find the current in I3 resistor by using kirchhoff's laws. problems: -when i try to use norton theorem to check for my answer and my answer is IN=2.855A=I3 but when i use kirchhoff's law i get I3=0.645A. -i don't know where is the problems...the current for norton theorem and kirchhoff's...

Homework Statement If I have a coaxial transmission line, with a resistor halfway through, and another resistor at the end, how do I calculate the reflection coefficient for the spot where the resistor is halfway? Here is a diagram of what I mean. Dashes and dots are are the lines, and }...

Preface: Newbie here. Sorry if this has been asked before - I did have search but couldn't quite find what I was after. Also, I'm not putting this into the electrical engineering section because I don't want what will inevitably be an electrical engineer's answer =) Here goes: Voltage across...

I have a 400A (125VDC) charger that feeds a battery bank and a few DC panels (critical). This poor design has the panels being fed from the high side of a 600A breaker that is between the charger and battery bank. I need to take the battery off line for a load test but the problem I'm going to...

I am having a lot pf problem to attempt this question, please help me, i am stuck..! The power loss P in a resistor is calculated using the formula p=v^2/R The uncertainty in the potential difference V is 3% and the uncertainty in the resistance R is 2%. What is the Uncertainty in P...

Homework Statement A resistor of resistance R is connected to an AC generator with EMF(t)=(EMF_max)sin((w_d)t). (a) Write Kirchhoff's Loop Rule for this circuit at a particular instant of time. Is your result a differential equation? (b) Find the current as a function of time. Now...

Homework Statement The question itself doesn't make sense to me, it says to find emf but the answer box has V= ? problem is an attachment. Homework Equations I=e/(r+R) Ir+IR=emf P=VI The Attempt at a Solution If it wants voltage that's simple P=I^2R P=V^2/R V=54.8V if...

Hi guys, new here. I was wondering if anyone knew of a way to trick a 12 volt transformer into seeing more load. I have these lights http://www.lowes.com/pd_172832-24969-800CBL5N_0_?productId=1207073&Ntt=tiella&Ntk=i_products&pl=1&currentURL=/pl__0__s?newSearch=true$Ntt=tiella$y=0$x=0" and it...

If a current of .587e^j1.12 is passing along a 200ohms resistor, how would I go about calculating the power dissipated in the resistor?

Homework Statement Determine the value of the ballast resistor is satisfactory if a 5Volt 0.5 watt zener diode is used in the circuit sorry can't upload a picture but basically VS = 15v min to 20v max R ballast = 90 ohms (series with zener) and R load (in parralel with Zener) is 50...

Homework Statement http://farm5.static.flickr.com/4117/4775531139_8d4dd954f5_b.jpg Homework Equations I = V/R E = I1R2 = I2R2 =I3R3 The Attempt at a Solution I got 5.22 ohms for part (a), but I'm not sure how to go about calculating the amps through a specific resistor.

Homework Statement Consider the electric circuit shown in the figure. Assume that V = 10.4 V, R1 = R2 = R3 = R4 = R5 = 3.00 Ohm. What is the electric current flowing through resistor R2? I couldn't upload the figure, but you can find it on my cramster.com post...

Electrical Engineering-- Capacitor Resistor Circuit Homework Statement Hello all. First time posting so excuse any fourm faux pas I may make. I was wondering if anyone could lend some help with the circuit below (ignore the *, they are just space holders to prevent reformatting of the...

Homework Statement Number 15 http://lookpic.com/d2/i2/386/kFYE2mOH.jpeg [PLAIN]http://lookpic.com/d2/i2/386/kFYE2mOH.jpeg Homework Equations Rs=R1+R2+R3 Rpar=1/r1+1/r2+1/r3 I=V/R The Attempt at a Solution 1/(1/5+1/10+1/5)=2 Rtotal=7 I=21/7 I=3 I don't know what else to...

i have a question about resistors. i thought they were described by their resistance - 20 ohm, 40 ohm, 2 Megaohm, etc. how come I see "power" values on resistors? for example my lightbulb says 40 watts. but i thought the power is simply P = V^2/R and that would depend the voltage of my power...

Homework Statement Why is it that the output is equal to V+ (when the switch is open) in diagram A, if there is no current flowing? Why is it that A (1/0) is used by convention? I mean the lamp I got at home has a "0" for off and "1" for on, on the switch. This is confusing me...

Homework Statement See figure Homework Equations Rs = R1 + R2 Rp = (R1*R2)/(R1+R2) The Attempt at a Solution I tried completing one repitition of the pattern to see if I could figure out what the Req would be so: R + R in series on the end so 2R // R so 2/3R in series with R...

Homework Statement For the circuit below (attached) plot the amplitude of AC voltage across resistor as a function of the angular frequency of the ac source. Homework Equations ZR = R The Attempt at a Solution I'm not really sure about any of this. Across the resistor, the complex...

What is the resistance of a non-ohmic resistor (lamp) in v-i graph given a voltage? I thought it would be the gradiant for specific voltages. But apparentlly it is the ratio of the specific voltage/current which makes sense too. So what is the correct out of the two?

Homework Statement How would you calculate the voltage at a specific resistor given that it's a parallel circuit.

Homework Statement A problem from a translated Sears-Zemansky, 1965, 14-10: A conduction coil with inductance of 15 miliHenrys and resistance of 10 Ohms, is connected in line with a capacitor of 200 microFarads and a resistor of 12 Ohms. The circuit is supplied with an alternating current of...

Homework Statement What is the resistance of the (semi-)infinite resistor chain below, between points A and B, if R = 25 ohms? The Attempt at a Solution I am not sure where to begin exactly, but I am thinking of this formula: VAB=VB-VA=∑ε-∑i.R or...

I have a circuit that uses a resistor to drop the input voltage. From my calculation, the power dissipation thru the resistor is less than it's wattage rating but yet the resistor is hot to the touch. Should I use a bigger resistor because it's too hot to the touch or should I keep using it...

Homework Statement heres a picture of the problem. Please don't give me the answer just tell me what are the steps to complete it. thanks. http://i307.photobucket.com/albums/nn296/alan1592/download-1.jpg Homework Equations V=IR The Attempt at a Solution 1/6+1/3=2 Ohms

Hi! A little food for thought for people who like high school physics labs.. In a standard rheostat(I have seen only the cylindrical one..the question is about rheostats of this shape..), we find a metal wire wound over a cylindrical core. The wire is wound with very closely spaced turns...

Hi all -- I had a question about the Nyquist-Johnson noise formula: \[ E_{\nu}^{2}d\nu=\frac{4R_{\nu}hd\nu}{e^{h\nu/kT}-1}\] which of course can be approximated for most purposes as $ E_{\nu}^{2}d\nu=4R_{\nu}kTd\nu$. I'm just wondering why the formula has $ exp(h\nu/kT)-1$ in the...

1. In the case of a current source in series with a resisitor, can this be transformed to just a current source with 0 resistance, or is the resistance infinity in the Norton equivalent? Homework Equations The Attempt at a Solution My teacher told us this in class but i can't...

Homework Statement Determine the potential \phi inside a resistor of length l and radius a. Also determine the current density J, resistance R, surface and volume charge density Pe and Pes. The resistor is homogeneous. Homework Equations The Attempt at a Solution V=Ed, d=l here...

Homework Statement Given that the souce voltage = Vo, find the Current at resistor 4. Homework Equations For resistors in series, I = constant For resistors in parallel V = constant The Attempt at a Solution So I gather that since the block containing resistors 2-5 is in...

I am trying to plot the graphs of power dissipated in pure resistor , pure capacitor and pure inductor against time . My question is when i plot the voltage and current graph for pure resistor , i know they are in the same phase , but V0 is greater or Io is greater , i think Vo is greater...

Homework Statement [PLAIN]http://img297.imageshack.us/img297/7053/96217079.jpg given this circuit find the current on R1,R2 and R2Homework Equations I = V/RThe Attempt at a Solution i applied kirchhof's law and I have this: 36 - 5*I - I1*4 = 0 36 - 5*I + 20 - 2*I2 - 14 = 0 20 - 2*I2 - 14 +...

Here is the problem and the equations I feel are relevant. The instructor was not clear on whether or not R2 was moving with velocity v, but I assume so because something must be moving (I think). Can somebody give me some instruction on where to go from what I have...

Homework Statement please see attached picture. Homework Equations The Attempt at a Solution

Homework Statement There is a Battery connected to a single loop circuit containing two resistors, R1 and R2, and one capacitor L. After a long time, the battery is removed, so there is a single loop circuit with just two resistors and a capacitor. What is the current going through R1...

I have a unit that measures temp with a thermistor. I want to use it to measure voltage. I am trying to build a circuit to emulate a thermistor. Here are the parameters. 24v control = 37.8K. 1v control change = -1k so there is an inverse relation ship. Control voltage range = ideal is 6...

URGENT: Finding the Current and Power across each Resistor in a Complicated Network Homework Statement For the circuit below, a 12 V batter is connected across the points a and b. Determine the following: a) the equivalent resistance between points a and b b) the total current flowing...

Homework Statement Find the voltage across R1 (see attached image). Note that all values are known. Homework Equations Voltager divider might be used. I hope KVL doesn't have to be used here. The Attempt at a Solution My problem is that I don't know if the current from I1 is...