Resistor Definition and 879 Threads

Hi, forum. This is my first time posting and I was curious if someone would mind looking over my work for a problem? I need to find the current passing through R1 and R5, the picture below shows the problem and my attempt at a solution. In the picture there are three main equations I used...

Homework Statement http://img832.imageshack.us/img832/6302/20285200.jpg Uploaded with ImageShack.us Homework Equations The Attempt at a Solution I'm unsure where to begin with this. I need to find the value V across the resistor and I'm unsure how. What effect do the diodes...

Hi everyone, I hope this question hasn't be asked and answered already in this forum, I searched through all related threads but I couldn't find an answer specific enough to my question. Consider a simple circuit with a DC battery and resistor. When the electrons (the charge carriers in...

http://img684.imageshack.us/img684/8362/opamp2.png Lets say we are given a non-inverting Op-Amp The gain of this circuit would be A = 1 + (R1+R2)/R3 if the switch is off. What happens when the switch is turned on? It shorts the R1 and R2 resistors am I correct? Does this mean that R1...

How do I reduce this resistor network. The input current and the return current should be equal. But in this case, some current will also flow to ground. Can't get my head around this.

I am try to measure the voltage from a high impedance source with a regular voltmeter with an input impedance of 10 mega ohm. But the voltage being measured is inaccurate. Is it possible to change the resistor value inside the voltmeter to 100 mega ohms to get a more accurate reading?

Homework Statement Find the current in each branch of the circuit shown in the diagram (attached) if: V1 = 1V V2 = 4V R1 = 1\Omega R2 = 2\Omega R3 = 1\Omega Homework Equations V=I*R The Attempt at a Solution Okay, so I know that the voltage will be even across the parallel...

Homework Statement The relationship between resistance with temperature is expressed by the equation of R= R0[1+ α(T-T0)], where Ro is the resistance at the reference temp. T0 and α for the resistor material has been determined to be 0.0048 ± 0.1% oC. In the range 0 to 100* C, in which we...

Hi, I've understood the basics of an RLC circuit but it seems that when actually putting them into practice I'm advised to put an additional resistor in before the (RL) and C that are in parallel with one another with no explanation. What's the purpose of this resistor and what does altering its...

Homework Statement A network of resistors has a pair of input terminals AB connected to a dc supply and a pair of output terminals CD connected to a load resistor of 120 ohm. The resistances of the network are AC=BD =180 ohm, and AD=BC=80 ohm. Find the ratio of the current in the load...

Homework Statement A series combination of a 22.0 mH inductor and a 145.0 ohm resistor are connected across the output terminal of an ac generator with peak voltage 1.2 kV. (a) At f= 1250 Hz, what are the voltage amplitudes across the inductor and across the resistor? (b) Do the voltage...

Homework Statement A 2 micro F capacitor with an initial charge of 5.1 micro C is discharged through a 1.3 kohm resistor a) calculate the current though the resistor 9ms after the resistor is connected across the terminals of the capacitor. b) what charge remains on the capacitor after 8ms...

Homework Statement what is the current in each of the branches in this circuit: [PLAIN]http://img593.imageshack.us/img593/893/resisotrcurrentquestion.th.jpg http://img593.imageshack.us/i/resisotrcurrentquestion.jpg/ Homework Equations v=ir r1+r2 = r3 1/r1 + 1/r2 = 1/r3 v1 + v2 = v3 ? The...

I have a 12v switching transformer; one of the legs on a black brown silver gold 2w resistor is broken off. I have had zero luck finding a standard .01 2w resistor. I did find a current sensing resistor at the values, but should it be used. The resistor in the power supply is ceramic, I think...

Homework Statement Three batteries and four resistors are connected in a loop as shown (see attachment). What is the voltage drop across the top left resistor? Homework Equations V = IR The Attempt at a Solution This is part 3 of the 3 questions for this problem. On the other...

I don't know English well(I'm from russian speaking countries) but I try to explain the problem(and practise my english too) Homework Statement Transfrom scheme into eq. scheme with one EMF and one resistor. Homework Equations Where is the series configuration of resistors and where is...

Ok, I'm not an EE student, nor do I really understand all of the P=IE^2 stuff concerning power and resistance, etc. My question is regarding the power dissipation abilities of resistors in paralell. Let's say I have (10) 100ohm/5w resistors in paralell. Would this effectively be a 10ohm load...

I have a 12vdc, 5Amp power supply and need to connect to a 12vdc, 40 watt electromagnet. I put a SPDT relay switch between the power supply and the electromagnet to turn it on and off. Do I need to put in a shunt resistor or something else to protect the magnet and the power supply? How do I...

Homework Statement For the circuit shown in the figure below, calculate the current I4 through the 2.18 resistor. As shown, R1 = 4.20 R2 = 8.12 R3 = 6.10 R4 = 2.18 I1 = 3.16A and E1 = 18V I couldn't get the picture on here but I will describe it: It is a parallel circuit, with...

Homework Statement Consider the electric circuit shown in the figure. Assume that V = 21.7 V, R1 = R2 = R3 = R4 = R5 = 6.00 Ohm. Part 1) What is the equivalent resistance of the circuit? Part 2) what is the electric current flowing through R4? Homework Equations Series and parallel...

Homework Statement We have built a circuit with an ac source containing a resistor in series with a parallel RC combination, we have measured the voltage across the first resistor and the voltage across the RC combination with a high and a low frequency. 80Hz: V0 = 2,325 V en Vm = 2,780 V...

Homework Statement Calculate the currents in each resistor in this figure: http://session.masteringphysics.com/problemAsset/1084690/2/GIANCOLI.ch26.p32.jpg Homework Equations Kirchhoff's rules In a closed loop: the sum of voltage is 0 A a junction: the sum of current is 0 The...

Homework Statement Find the equivalent resistance of the circuit as shown in the diagram below; where R1 = 4.0 , R2 = 3.0 , R3 = 1.0 , R4 = 3.0 , R5 = 2.0 , R6 = 4.0 , and R7 = 1.0 . [Ohm] Homework Equations Parallel and series resistance equivalence Req= 1/R1 + 1/R2 + 1/R3 ... etc...

Homework Statement The battery has negligible internal resistance http://www.webassign.net/tipler/26-50.gif Find the current in each resistor. Find the power delivered by the battery. Homework Equations V=I/R P=IV The Attempt at a Solution Now I feel like this problem is ridiculously simple...

I have a source of 800 Kilo Ohms and I want to power an LED with that source. Which I would presume the LED would have a resistance of 9.5 to 10 Ohms if I'm correct. When I connect the LED to the source the voltage drops from 12 volts DC to around 1 volts DC. If my thinking is correct the reason...

Homework Statement http://img214.imageshack.us/i/124w.png/ Homework Equations \[R = \frac{V}{I}\] P=VI The Attempt at a Solution a) Using KVL around the loop, I got V_{R}=6.3 V . Then I used \R = \frac{V}{I}\ and got R = 1.4 ohms. b)I used P=VI and got P = 28.35 W...

Homework Statement A non inductive resistor takes 8A at 100 volts. What inductance of a coil of negligible resistance must be connected in series in order that this load can be supplied from a 220 volt 60 Hz mains. Homework Equations Z^2 = R^2 + XL^2 R=V/I XL = 2pi(frequency)...

Are the following Req's between the two nodes equivalent? I'm pretty sure the first and seconds ones are, sort of sure the third is, and a little sure the fourth one is. The r's are the resistors. I'm sorry that the pictures are so crude, I couldn't attach my MS paint picture's jpeg or png Bonus...

Hi, I'm doing a IB Physics internal assessment on how the length of a tube of playdoh in a straw relates to the resistance of that tube. I tested it by connecting a 150 ohm resistor to one end of the tube of playdoh and connected the two to a power supply. My data at the different lengths all...

Homework Statement A lamp is marked 12V/10W. the lamp is connected to 24V accumulator. in series with lamp you must then connect a resistor. Calculate the resistance of the resistor. Homework Equations The Attempt at a Solution

Homework Statement The op-amp in the circuit shown is ideal (please see attachment). The adjustable resistor RΔ has a maximum value of 160 kΩ and α is restricted to the range of 0.22 ≤ α ≤ 0.7. (a) Calculate the range of vo if vg = 40 mV (b) If α is not restricted, at what value of α...

Homework Statement What would the current I1 be in the figure below if the 18 Ω resistor is shorted out (resistance = 0)? Let r = 1.0 Ω. Homework Equations I used Kirchhoff's RuleThe Attempt at a Solution I figured this problem out, but I had trouble, and I'm not sure I understand why the...

Homework Statement How much energy is dissipated as heat over 2 minute time interval by a 1.5 k(ohm) resistor which has a constant 20 V potential difference across its leads? Homework Equations deltaV=-Ed The Attempt at a Solution In my notes this is the only equation that seems...

Anyone could suggest which resistor and capacitor value that used most in home-brew project? Those project basically deal with LED and PIC. I want to buy them in bulk, but I do not know how to assort them. I wish to buy like 50 resistors and 50 capacitors. Looking forward for your help.:)

When charging the capacitor, what is the purpose of connecting a resistor in the circuit? Is it to slow down the rate of charge entering the capacitor, therefore lowering the potential difference across it? I think that doesn't make sense. Or maybe to encourage the flow of current in the...

Homework Statement A 39.5 uF capacitor is connected to a 47.0 ohm resistor and a generator whose rms output is 25.2 V at 60.0 Hz. Calculate the rms current in the circuit. (also asks for voltage drop across resistor, capacitor and the phase angle for the circuit, but I mostly want to get...

how can i increase the voltage, without changing the current... do i increse the current or decrease it V=IR--->(V/R)=I i just increase the resistance

http://www.mediafire.com/?dqjlrfbu0m63l67 Hey I've been trying to recreate this circuit on a breadboard for a while and it never works... Then I try to make it in a circuit simulator and it still doesn't work. Anyone know if the circuit actually works? Also I believe this circuit can be used...

Homework Statement Capacitor voltage as a function of time is recorded for a simple direct current RC series charging capacitor. How could we determine the resistance of the resistor?Homework Equations q=Qe^\frac{-t}{RC}The Attempt at a Solution I understand the question I'm just having...

(another problem but less differential equations-sy) Consider a circuit where there is an effective resistor in parallel with an effective capacitor. Each effective capacitor consists of two capacitors in series, same for the resistor. Now, when the capacitors are uncharged, all the...

I am trying obtain some equations for an RC circuit that has a resistor R1 after a battery, which then splits into a capacitor C and a resistor R2 (the circuit closes after this point). When I try to seek help online, the resources are quite unhelpful. I cannot seem for example, obtain any...

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.