Resistor Definition and 879 Threads

Forgive the title, I was unsure of how to briefly describe the problem. Attached are diagrams. Homework Statement The device shown in Figure P2.5 can be modeled as a current source in parallel with a resistance. When this device is connected to a 5[mA] current source, so that...

Hello, I am a computer engineer that specialized more in software but I am trying to remember the electronics part. In the book I read there is an exercise where a diode (forward-biased) is connected in parallel with a resistor and then both of them are connected in series with another...

Find the current across the 20 Ω resistor using the image. http://s1078.photobucket.com/albums/w488/maddy31595/?action=view&current=Untitled.jpg So my teacher gave us this problem and the answer, but didn't go over how to get the answer. I have no idea where to even start. Help?

Problem: An Si resistor is at 300Kelvin, and is 100μm long, 1μm thick, 5μm wide. The conductivity is 7.128 Ωcm. The resistance is 28058Ω. A voltage of 5v is applied. What is the drift velocity of the electrons, given that n = 1.01x103? Other constants: μn = 1350 cm2/Vsec μp = 450 cm2/Vsec...

I am trying to repair this device and have determined that the issue is with this melted resistor... In order to find the correct replacement i need to determine specifically what resistor this is.

Hi all, I want to measure the white noise produced by a resistor in my circuit. In order to do this I did the following: 1. Ground the excitation voltage of the circuit and measure the white noise voltage produced by connecting the output of the circuit to a 8.5DVM 2. Subtract the Avg DC...

Homework Statement Use resistor simplification to find current across the 10ohm resistor Homework Equations V=ir p=vi The Attempt at a Solution Any help you can give me is much appreciated. When I did it i got down to a parallel circuit with a 30ohm and a 100ohm but didnt get a...

Homework Statement http://i134.photobucket.com/albums/q100/megajette2/Resistornetwork.png Homework Equations parallel resistors share the same nodes or terminals and simplify to (a*b)/(a+b). in series resistors values are added. The Attempt at a Solution...

i'm given a circuit that contains a 15 volt battery and a resistor that has a power rating of 1/4 watt and a resistance that must be greater than 1 kohm. I'm told that no matter how i set it up, i cannot exceed the 1/4 watt power rating of the resistor. this makes sense. i work out the max power...

Homework Statement A series circuit consisting of a 10 ohm resistor, a coil and an ideal capacitor is connected across a 200 V, 60 Hz power supply. The current drawn is 8 A. The voltage across the coil is 120 V and its power factor is 0.8 lagging. Determine (a) the voltage across the...

hi just needed to know if the power dissipated by a resistor is equal to the total voltage. I am having a hard time understanding a problem i was given, and i know the formulas to find power dissipated, but i can't use P = I squared * R or P = V squared / R for this question... " A 10 ohm...

Hello every body... Consider two port system having a resistor (can it be called two port system?)... ____---->I1________________I2_<----_________...

Friends: I am wondering about heat dissipation when you have imaginary numbers. Lets say a current I = (3 + 4j) Amps is going through an impedance Z = (2 + 3j) Ohms. What is the amount of heat dissipated by the impedance? I think that you take the magnitude of the current, |I| = 5 Amps, and...

STK 4191 amp. burning resistor :( I just built a STK 4191 amp. when i supply power a 100Ω resistor (1w) near the IC starts smoking. there're no short circuits across the ICs pins or anywhere on the board and i took all precautions when soldering the IC on (was done with heatsink + 40mm fan...

This question is in reference to the diagram here: http://imageshack.us/f/17/ecediagram.jpg/ Find the average power dissipated on the resistor. Assume Vth for the diodes is 1V, N1 = 1000, N2 = 100, the transformer is ideal (non-lossy), and V(t) is a purely sinusoidal voltage with frequency...

Long story short, I am college student with limited capital. My high beam went out on my 2008 VW rabbit and melted the headlight enclosure. The cost to fix the unit is $500 which I do not want to spend for a head light. The bulb is a 12v 55w unit. There is a bulb out light I would like to get...

Homework Statement Calculate the current through the resistor of resistance for circuit B. Express your answer in terms of EMF, R1, and R2. http://imageshack.us/photo/my-images/163/screenshot20111112at110.png/" Homework Equations Kirchhoff's Loop and junction rules The Attempt at a...

Homework Statement Hello forum, please see the attached image. This problem amounts to finding the equivalent resistance for the circuit and using Ohm's law to solve for the current. Homework Equations V=IR The Attempt at a Solution What I really need help with is learning how...

Problem description: The problem is Kotitehtävä 7 in the attachement. The idea is to calculate the output power (both P and Q) of the current source. Attempt: I know the current through the current source (obviously) and want to calculate the voltage over it to get the power. I have...

This isn't a homework question but it is a formula from a book I have been using to study, so I'm posting it here. Here is the circuit and formula - I don't understand why the voltage drop of 0.7 volts across the diode is being used as part of the formula to work out the current...

Homework Statement http://i.imgur.com/H20el.png Homework Equations KVL The Attempt at a Solution When I solved the equation for V0, I got V0=2V. Is this correct? If it's not, I'll upload my work. Thanks!

Homework Statement A charge Q is placed on a capacitor of capacitance C. The capacitor is connected into the circuit as shown in the figure below, with an open switch, a resistor, and an initially uncharged capacitor of capacitance 3C. The switch is then closed and the circuit comes to an...

Homework Statement In the circuit as shown in Figure 4, there are three independent sources and five ordinary resistors. (a) Determine which of the circuit elements are sources and which are resistors? (b) Determine the value of the resistance for each of the resistors...

Homework Statement I have to determine the resistance of a cone shaped resistor with the following dimmensions: Height at the first end: 1mm Lengdt: 250mm Height at the last end: 0.5 mm Rho: 14.5^10-6 Ohm*m Homework Equations \Omega = \frac{\rho \times L}{A} The Attempt at a...

Homework Statement Your task is to design a "dummy" indicator light for your car. The cheapest bulb available is a #47 incandescent lamp rated at 6.3V for 150 mA. The problem is, your car produces 13.5 V when it's on. Choose the nearest 10% resistor that will reduce the voltage across the...

Homework Statement So I need to find the total voltage across the current source. Looking at the attachment, I took front square: B_______C ......|.....| ......|.....| ......A_______D back square: E_______H ......|.....| ......|.....| ......F_______G Homework Equations node analysisThe...

Homework Statement The current in amperes through a certain type of non-linear resistor is given by I=0.05V^3, where V is the potential difference in volts across the resistor. This resistor is connected in series to a fixed resistor and a constant voltage source of 9V is connected across...

Homework Statement An ideal battery with an emf of = 14.0 V is connected to a network of resistances with R1 = 6.00 , R2 = 12.0 , R3 = 4.00 , R4 = 3.00 and R5 = 5.00 . What is the potential difference across R5? __R1__ __________R3__ __R2__ __R4_____R5__ __emf battery__...

Homework Statement I am given a resistor, 40KΩ + or - 20%. I know the uncertainty formula but it involves two variables, but not how to combine these together to get an answer. Not to mention, isn't the uncertainty formula redundant since I know the 20% over or under? Homework Equations...

hallo everyone, i have here a simple problem that i cannot solve. This is the problem: A resistor of 46 Ω is connected to the end of a power cable. The voltage a the begin of the cable is 230 V. The length of the cable is 25 m The copper area is 1.0 mm2 The specific resistance of...

Homework Statement given simple circuit with V the voltage connected to a resistor with area A, length d and electrical conductance: b*e^-2x/d after my computations the resistance R=d*(e^2-1)/(2bA) Homework Equations what is the electrical field E in the center of the...

Homework Statement Find Req. Homework Equations Series: R1 + R2 + ... Parallel: 1/(1/R1 + 1/R2 + ...) The Attempt at a Solution There's no solution for this one in the book but I'm thinking that I can break this up into two parallel sets. Parallel1...

Homework Statement An electric current of 10A runs for 1 minute through a 20 ohm Resistor which is maintained at 10 degC by being immersed in running water. What are the entropy changes in a) the resistor b) the running water c) the universe Homework Equations P = I2R dS = dQ/T...

Homework Statement Hey everyone. I might be overthinking this one, but I thought I'd post it. (sorry for the crappy MS Paint sketch!) I need to find the current through R3 Homework Equations V=IR \SigmaV=0 (around a closed loop) \SigmaI=0 (going into a junction) The Attempt...

This will (maybe) be an easy question to answer. Here is my situation: I have a 12v 200mA capacity transformer (wall wart) that I am using to power up a relay which takes about 5mA and has an input voltage range of 5-24v. Basically I need to burn off the other 185mA or so of the transformer's...

Amount of charge flowing through a resistor? the current through a resistor is 3 mA. What charge will flow through it in 200 seconds? if the resistor has a resistance of 2.0 kΩ what will be the power dissipated in it? for the first one, i have no idea. i can't seem to find any formula...

Homework Statement Suppose a current of 1 A is flowing through a resistor. If this makes the resistor heat up, will the current through the resistor increase, decrease, or remain constant? Assume the voltage applied to the resistor is constant. Homework Equations The Attempt at a...

Consider a resistor with current running through it for some time in a constant temperature bath. I understand that the change in entropy of the resistor is zero because there is no change between the initial and final thermodynamic state. However, I am trying to come up with a reversible...

In my battery-powered lawnmower there is a circuit breaker. I have replaced the breaker, and when I cut apart the old one I found a 68 Ω resistor in parallel with the breaker switch. My question is, what is the purpose of this resistor? Here is the basic mower circuit: (Imagine that...

Suppose we have a bulb or a forward-biased LED (or any other component) which needs no more than say 3 V across it to operate. And we want to connect it in series with a voltage source of say 12 V, and a resistor. So without this resistor, the LED would quickly burn out and be destroyed. I've...

Homework Statement Two resistors, R1 and R2, are connected in series across a potential difference, ΔV0. Express the potential drop across each resistor individually, in terms of these quantities. The Attempt at a Solution R1 + R2 = Req I = V0 / Req drop at V1 = V0 / (req) * R1 V2...

I need help calculating the R values for this circuit from the following article: AN HIGH RESOLUTION RESISTIVE PROBE FOR NONLINEAR ANALYSIS OF TWO-PHASE FLOWS L. Cantelli, A. Fichera, A. Pagano This is only a section of the circuit, there is more but I'm only interested in this part of...

How is the resistor value for an IC Enable/disable pin decided. I always use 10K. But not sure how to calculate it . Do you connect Enable bar directly to ground or thru a resistor.

Homework Statement For the following questions, use the schematic below, where R1 = 3.0 Ω and R2 = 17.0 Ω. (a) What is the equivalent resistance between points A and B for this combination of resistors? 3.83 Ω (b) A 8-V emf is connected to the terminals A and B. What is the current...

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...

Many years having passed since I last looked at an electrical circuit, I been asked to design an electrical circuit at work. We make tonic water, and the idea is to create a holder for bottles with a built-in UV light rigging. Due to the relative efficiency, robustness, cheapness etc, I am...

In trying to figure out what's Vout, do I discount R4? I don't believe any current will flow through there. http://img825.imageshack.us/img825/7236/vinvout.jpg

Homework Statement A Pt-resistance thermometer is used to measure temperatures in the range 0°C to 100°C. The electrical resistance of the thermometer is 2 Ω at 20°C and 6 Ω at 100°C. It is necessary to measure the temperature to an accuracy of ± 0.1 K. How accurately must the electrical...

I am looking to design a circuit, most likely with a transistor, to act as a voltage controlled rheostat. The controlling voltage can range from 0 - 3.3 v and I am trying to get a resistance range of about 200 - 5500 ohms. The circuit should have fairly high input impedance since it will be...

Homework Statement I figure I will just combine these two questions into one topic. 1) The energy stored in a capacitor is .5CE^2, where E is the voltage. Wat is the instantaneous power dissipated in a resistor R through which this capacitor discharges? Show that the total energy dissipated...