Resistor Definition and 879 Threads

First off.. this is my first attempt playing with this kind of stuff.. please have a bit of patience with me :) I'm looking to make a costume out of LEDs for burningman.. bought a 1000 of them off ebay and when I connect them the 9V battery I'm guessing is too strong for it and burns the...

Hi, This may sound a little silly but I have a circuit with 1 resistor which is a 1k ohm resistor and is connected to a 9 Volt battery.I found the amps using ohm's law I = E/R which equals 9 amps.I have also used a multi-meter to see the resistance and I'm a bit confused a resistor is...

I can't find the current in the following picture, please help me to find it and show the step, thanks.

Homework Statement Show that V across Resistor Rkohms is: (11R) / (3.96 + 4R) V The circuit is a 5V cell in series with a 1.8k resistor. Following the 1.8k resistor are a 2.2k and Rk resistor in parallel with each other. The wires then rejoin and return to the cell.Current through the circuit...

I recently bought this resistor: http://www.radioshack.com/product/index.jsp?productId=12573233 I want to hook it up to about 50V DC, but I want to know if this would be harmful to the resistor. According to the description it can handle up to 800V, but its power rating is only 25W. This...

Hello everyone, this is my first post, and I hope I have put this in the right area. I am looking to understand something about the behavior of a low pass filter. When an alternating current is passed through a low pass filter, the higher the frequency, the lower the voltage output of the...

Homework Statement The question is to find Equivalent resistance between opposite ends of a cubical resistor network . each resistor of resistance R . I am referring to this website here http://mathforum.org/library/drmath/view/65234.html I am halfway through it but I am stuck at a...

Homework Statement The problem involves a battery of emf 10V [with no internal resistance] and a combination of resistors. Here is the diagram provided: A picture of the diagram can be found here: http://gyazo.com/7791710d0645de38cfab59f0ac4740ec (Couldn't get the image feature to...

Homework Statement Helping someone regarding this Qns: A Battery is formed by four 1.5 V identical cell in series. When a external resistor of 31 Ohm is connected across he battery, the current is 280 mA. Find the internal resistor of each cell. Can someone help to solve pls? Thank you...

hey guys I have been given a piece of equipment to fix, that is not charging its battery. I am trying to map out its small circuit board to try and understand what it is thinking so i can figure out what isn't working. I am having trouble tracking down the resistor network specs so I can draw...

Hello, I am trying to work out the resistor values for an 'O' attenuator. I am using the attached formula to work out resistor 3's value. My values to insert into this formula are: Input impedance (Z1) = 50 Ohm Load impedance (Z2) = 600 Ohm a =1.995 However when I substitute these figures I am...

I have a diode with a resistor in parallel(R2), but also diode resistor circuit has a resistor in series with it(R1). I have uploaded a drawing as well but I think it takes a bit of time for them to be authorised. The values of the circuit are Vs = 20v R1 = 3kΩ R2 = 470Ω Diode = Has a Volt drop...

the question is to find the magnitude and phase angle of the resistor voltage in the circuit below : http://img513.imageshack.us/img513/1035/ee204.jpg i want you guy's to check my solution please . thanks .

I have been given this problem, I've simplified it down to a total resistance however I'm unsure on whether I have done it correctly. Any pointers would be nice, thanks. First of all I added the two resistors together in the top right as they are series. I then used that product with the...

Homework Statement Find Rth, at the terminals shown on the diagram Homework Equations Series resistance = R1 + R2 + R3 +... Parallel Resistance = 1/((1/R1)+(1/R2)...)) The Attempt at a Solution When attempting problems like this, I was told by teachers and the textbook to...

Homework Statement ε[1]=12v internal resistance[1]=.016Ω ε[2]=12v internal resistance[2]=.012Ω some unknown resistance 'R' in a stand alone resistor. a) what value of 'R' will make the terminal-to-terminal potential difference of one of the batteries zero? b) which battery would it be...

http://dl.dropbox.com/u/33103477/Resistor.png For the first bit first I solved the equation \frac{dI}{dt}=\frac{U-RI}{L} I(t)=\frac{U-C_2e^{\frac{-t}{L}}}{R} Now I put in T(0)=0 to work out the constant and I got I(t)=\frac{U-Ue^{\frac{-t}{L}}}{R} Now here's the dodgy bit, I did...

Homework Statement The problem and picture are attached in an attachment A cube consisting of identical wires, each of resistance R, is put across a line with voltage V (Fig. 28-44). What is the equivalent resistance of the cube? What is the current in each of the wires? Homework...

Ok. I am adding this up time and time again and its just not making no sense. I am sitting here trying to brush up on technical math skills this week before i get my soldering iron so i don't mess nothing up. and here i am i can't understand the basics. I have a 20volt power supply and 4...

Homework Statement A coil of wire has 600 turns and is 5.5 cm in diameter is in a magnetic field that decreases from 2.2 T to 0 T in 6.2 ms. The axis of the coil is parallel to the field. The coil is hooked up to two resistors of 120 Ω and 200 Ω connected in parallel. What is the maximum...

Homework Statement I am supposed to find the circuit design for a first-order low-pass filter. The filter must be made of resistors and capacitors only (no inductances). Furthermore, the output voltage must be measured over a resistor or something in parallel with a resistor. Homework...

Homework Statement If you have a series 'light-meter' circuit with a cell EMF of 12V that must include both an LDR and a resistor only (in series), which way would you put them around to make this most effective and why? ~~~That is, would you have LDR then resistor, or resistor then LDR...

Homework Statement http://img138.imageshack.us/img138/6717/hwprob.jpg Homework Equations General intuition, KCL, KVL The Attempt at a Solution I've worked this out multiple ways to no avail. I think the easiest way to go about this is to set the left node to ground (0 potential) and go...

How does equivalent resistance from D to B is 3/4 R ?

Hi Guys, Given a resistor, I understand how to use the bands to calculate the resistance, but how does one tell what the resistor is able to handle. For example, I have a 51ohm resistor that I connected to a DC power supply. At 5V all was fine, but when I increased the voltage to 10V the...

Hi I am little confused by star resistors configuration. The problem is asking for equivalent resistor for the circuit. I have attached the image below (Image is little sloppy because I can't draw with a mouse :D). My logic is as follows: First I calculated R1 and R2 as parallel...

Homework Statement A series RLC circuit is connected across a 6.70 kHz source. The 1.50 H inductor and the 1.35×103 kohm resistor are fixed whereas the capacitor is variable. At what capacitance will the current in the resistor be a maximum? Homework Equations No idea.. The Attempt at a...

How to calculate gate resistance, Rg in the JFET amplifier circuit? And What is the function of Rg?

Homework Statement Here is the accompanying diagram. Calculate the power delivered to each of the resistors in Figure P28.28 (E = 55 V, R = 5.0 .) ____W (2.0 resistor in loop with 55 V source.) ____W (5.0 resistor in loop with 55 V source.) ____W (5.0 resistor in loop with 20 V...

My physics teacher said the other day that, if you connect a capacitor and resistor in parallel with a battery, no current will go through the resistor, since the current doesn't like resistance and so will follow path of least resistance (to the capacitor). But then the next day, I think he...

Homework Statement Homework Equations Resistors in parallel and series The Attempt at a Solution I connected points which had the same potential. I'm not sure where to go from here tho.

This should be a simple question. If you have a series circuit in the following order: emf, resistor1, capacitor, resistor2 Are both resistors in series during the charging interval considering that they both have the same current through them? That is, would a resistance of resistor1 +...

Question b. in paint doc. My answer is: Becuase they said the current in question a. through the 6.0 ohm resistor is 1.0 A I am going to say the only two that will change is resistor 7.0 Ω and the newly replaced 3.0 Ω resistor... I am saying the current through the 6.0 ohm resistor will not...

Homework Statement When a resistor is connected by itself to an ac generator, the average power delivered to the resistor is 0.952 W. When a capacitor is added in series with the resistor, the power delivered is 0.477 W. When an inductor is added in series with the resistor (without the...

Homework Statement Hi guys, Im new here and I am working for the first time with with these applications. So, i have this resistor network https://www.physicsforums.com/attachment.php?attachmentid=44965&stc=1&d=1331497208 where R1=220 ohm and R2=330 ohm. I must find the electrical resistence...

How I am currently imagining it: In a simple circuit with just a battery and resistor the voltage of the battery sets the electrons off through the circuit at some speed and that speed is proportional to the voltage. The electrons then encounter the resistor. From these forums my...

Homework Statement The voltage V(t) [in volts] across a resistor in an electrical circuit at a given time t [in seconds] is given by: sqrt of something to the power of pi ^ that's the example i got in my book. Its just got the square root symbol, a space, and then a pi in an exponential...

Homework Statement The problem first asks to find potential difference across the capacitor after the switch has been closed a long time. Then it asks to determine the energy stored in a capacitor when the switch has been closed for a long time. I got both these answers right, with...

Homework Statement The capacitor is initially uncharged when the switch is closed for a long time. Calculate the current through R2. Then find the potential difference across R1, R2, and R3Homework Equations V=IR Iin=IoutThe Attempt at a Solution I first set up current going into top node (I1)...

Homework Statement The diagram below depicts an RC-circuit where C = 1.70 μF, R1 = 18.0 Ω, R2 = 10.0 Ω, and V0 = 2.0 V. a.) What is the current through R1 immediately after the switch S is closed? b.) What is the current through R2 after the switch S has been closed for a very long time...

my friend and i are doing a DP lab, we are trying to find a resister which reacts to water/ moisture in soil. a resistor that is directly proportional to the moisture in the soil thank you.

Homework Statement Find I1, I2, I3, I6 (intensities at R1, R2, R3 and R6) using Kirchoff's Tension Law. R1 = 1/3 Ohm, R2 = 1/4, R3 = 1/3, R4 = 1/2, R5 = 1, R6 = 1/4 E3 = 32V, E1 = 2V, E2 = 4V. http://dl.dropbox.com/u/9301772/Capture.PNG The Attempt at a Solution The schematic...

Today my teacher asked us a question Basically he said a match box was taped shut and a current was passed through the circuit a reading came up on the Ammeter, then the cell was switched around, and a current ran through the circuit but the Ammeter read a smaller reading than before. Why?

Homework Statement Find the voltage drop across a resistor and capacitor in parallel. I am trying to understand how to deal with this using complex numbers. I may have a completely wrong notion of complex impedance. I thought I could treat the complex impedance like resistance, then take the...

Homework Statement I do not understand the solution provided for this problem. Consider the circuit with five resistors and two batteries (with no internal resistance) shown in the figure. (b) Solve for the current in the 4-Ω resistor. Homework Equations loop law junction law...

Homework Statement 1) double the potential difference, ΔV 2) double the current, I 3) reduce the resistance, R, by 1/2 Homework Equations The Attempt at a Solution These problems are usually straightforward but I'm a little confused this time because I keep seeing all of the...

I'm currently studying electric circuits and can't find the answer to my question anywhere so far. I realize current is the flow of positive charge even though positive charges stay put in reality and that this is an old historic concept that is still around today because Benjamin Franklin...

Homework Statement Find the current in the 10.0 ohm resistor in the drawing (V1 = 24.0 V and R1 = 15.0 Ohm) Diagram: Homework Equations Kirchoffs loop ruleThe Attempt at a Solution well do i have to solve for both parts of the circuit if i just want to find the current at the 10.0 ohm...

Homework Statement A network of 5 resistors is constructed to a 12.0V emf. the total current in the circuit is 12.0A. determine, draw and label the configuration for the network of resistors R1=1ohm, R2=1ohm, R3=1ohm, R4=1ohm, R5=4ohm Homework Equations The Attempt at a Solution...

I'm learning the basics about electromagnetism, including that a changing electric flux through an open surface causes a magnetic field. Obviously a capacitor causes this, but doesn't a resistor like a light bulb (whose resistance varies with temperature and therefore time) also cause this?