Resistor Definition and 879 Threads

I was experimenting with resonant frequency of a series RLC circuit: 5V AC source 10 ohms resistor 100microF capacitor 46mH inductor Resonant frequency is calculated to be around 74.2Hz. So I set the AC source to resonant frequency 74.2Hz and measured the voltage across the 10 ohms resistor...

Homework Statement Consider the circuit shown in Figure P1.68. Find the current i_R flowing through the resistor. Find the power for each element in the circuit. Which elements are absorbing energy? V_source=12 V I_source=4A R=8 ohms Here is a picture of 1.68 Homework Equations P=IV...

I have some high voltage (300v+) analog circuits that I want to control digitally which requires the use of a voltage controlled linear resistor that can withstand high voltages. I don't expect the current levels to be that high. I originally settled on LDR optocouplers but it turns out they...

Homework Statement Find the maximal power on resistor R. Homework Equations [/B] The Attempt at a Solution I used Thevenin theorem. I found that Z_t=5+j10 , and U_t= 10-j10. The maximum power happens in this case when $$R=|Z_t| = 5 \sqrt{5}$$ , and I get that P=6.18, while the answer is...

Homework Statement $$R=5 \Omega , C =50 \mu F, L=5 mH$$ are connected in series on voltage source $$u(t)=150 \sin (1000t)+100 \sin(2000t)$$. Find the average power on resistor R. Homework Equations [/B]$$ P=\frac{U^2}{R} $$, $$ U_{ef}= \sqrt{ \frac{1}{T} \int_{0}^{T} u^2(t) dt } $$The...

I am ploting bode of resistor connected with DC source.So no freqvancy at all! The bode magnitude plot should be(or it should start from) 20*log(jw)=20*log(0) (jw=0 because we have dc source) what should be the value??for step of 5v... what should bode look like??

Hi, I have been at this problem for days and I can't seem to see what I am doing wrong. Here is the circuit layout along with my work As you can see I am running into problem getting values of current that do not add up equal to zero. My professor has never discussed how adding a wire like...

This isn't actually a homework problem, but it is an example in a my textbook that I have a question about... imgur link: http://i.imgur.com/2OglMH4.png Ok, I wanted to clarify some things. I understand that current flowing from a positive terminal to a negative terminal represents a...

Homework Statement When the resistor is R1, in the circle there is the intensity I1 and when the resistor is R2, the intensity becomes I2.Find emf and the inner resistance.[/B] Homework Equations I=emf/R+r The Attempt at a Solution I1=efm/R1+r I2=efm/R2+r efm is equal I1*(R1+r)=I2(R2+r)...

Homework Statement I must solve for the voltage across the resistor labelled R1 in the circuit above. The values given are the resistance of each resistor, the voltage of each voltage source and the current of the current source. Note: If referring to circuit loops consider them as being...

Q. It is a classical problem in current electricity .The resistor cube consists of 12 resistors, each having a value r. What is the total resistance between the two diagonally opposite corners labeled A and H on the cube? Ans. The answer to this problem begins with that due to symmetry points E...

A coil 3.65 cm radius, containing 560 turns, is placed in a uniform magnetic field that varies with time according to B=( 1.20×10^−2 T/s)t+( 3.05×10^−5 T/s4)t^4. The coil is connected to a 600-Ω resistor, and its plane is perpendicular to the magnetic field. You can ignore the resistance of the...

imgur: http://i.imgur.com/9VILpYL.jpg Now, I can easily solve this by applying the formula P_R = \frac{(\Delta V_R)^2}{R} and get all the correct answers. However, the answers feel strange to me intuitively. In the formula above, lowering the resistance increases the power that is dissipated...

Homework Statement Homework Equations P=V2/R P=I2R V=IR The Attempt at a Solution As the resistance of R increases, the potential difference across R increases, so the power dissipated in R increases too. But I can't seem to see how the power decreases afterwards. Is it because, as time passes...

Homework Statement What is the potential difference across each resistor? I know that I'll have to incorporate the V=iR equation but I don't know where to start though... My first attempt was with these: R1=4 R2=8 R3=5 R4=6 R5=3 24-I1R1-I1R2-I3R3+I4R4+I5R5=0 but this lead me nowhere so I...

Homework Statement Two resistors of equal rated voltages ##V_n##, and different rated powers ##P_{n1}= 50 W## and ##P_{n2}= 100 W## are connected in series on source of rated voltage. Find total power of a circuit. Homework Equations [/B]##P=\frac{U^2}{R} ##, ## R=R_1+R_2 ##The Attempt at a...

Homework Statement There are several parts, but the part I'm stuck on is: what happens if a jumper is placed from node A to node B? Calculate V_A and V_B, and magnitude and direction of the current through the jumper. The resistor values are R1=R2=2 kohms, R3=R4=1 kohm. Homework Equations...

Homework Statement Find the resistor that generates most heat. Homework Equations Principle of superposition. Voltage Div Current Div. Power = I^2R The Attempt at a Solution After aplying principle of super position and considering the voltage source in one scenario with current source open...

If an ideal inductor is connected directly (no resistor present) to a DC voltage source, why does it behave like a short-circuit at time t=0? If voltage across an inductor is related to the change in current (i.e. di/dt), then shouldn't the voltage across the inductor be very large at time t=0...

Homework Statement The equivalent resistance of the series combination of two resistors is p.When they are joined in parallel, the equivalent resistance is q. If p = nq, find the minimum possible value of n. Homework Equations 1/Rparallel = 1/R1+1/R2+... Rseries = R1+R2+... The Attempt at a...

Homework Statement Here is the homework problem I was given: The Attempt at a Solution Above is the work that I began, however, I have an overwhelming feeling that I am incorrect and also I don't know how to continue to the next part/parts. Would someone please help me? Thank you H

Homework Statement The problem and its solution are attached in the TheProblemAndSolution.jpeg file. Homework Equations V = RI G = 1/R The Attempt at a Solution I tried to understand what the solution said, but I'm still very lost. Here's what I'm stuck on.: When the solution says "Since...

For this problem I am just wondering if it is proper to "imagine" there is a voltage source from a to b so that one may say the 5 ohm resistor right after a is in parallel with the 6 ohm resistor connecting the two wires. If not, how would I go about solving this? Thank you in advance.

Find the voltage across the 4Ω resistor (resistor 3). This is all show in the pictures provided: I have started by reducing all the resistors into one resistor, but please take a look over my working and tell me if it's all correct. After reducing all the resistors into one, I used the...

Hello. Please see the attached image first. 1. The textbook seems say resistor to + input in this image is necessary to provide a return path to ground. I completely don't understand even what it mean. Could you help me to clarify this? 2. Instead of understanding directly what the book said...

Homework Statement Homework EquationsThe Attempt at a Solution I am surprised that this question came up, I haven't learned ac circuits yet. I don't know how to solve this. I just added both values and current and divide it by two, which gives me 1.5A, since I thought it's the average but I'm...

Hey there! I'm having some real trouble deciphering this complex resistor problem. I have heard of the Kirchhoff voltage and current rules and do know how to use them to solve some problems but I'm not sure how to apply them in this context, or if they are even used to solve this. As seen the...

Homework Statement The emf of a battery A is balanced by a length of 75 cm on a potentiometer wire. The emf of a standard cell, 1.02V, is balanced by a length of 50 cm. What is the emf of A? Calculate the new balance length if A has an internal resistance of 2 Ω and a resistor of 8 Ω is joined...

In BJT hybrid pi small signal model, we have a resistor "ro" between Collector and Emitter. This resistor is to include the change in collector current when there is a small signal voltage change between collector and emitter. (due to early effect) I am finding that all BJT hybrid small...

Good day , could someone please point me to a device that would have say two wire terminals and could interrupt the flow of current between them when a dangerous temperature is reached? the idea is simple , I built a lamp and I need some failsafe mechanism that would turn the lamp off when it...

Homework Statement http://i.gyazo.com/c6b73ca3a53b7d36bce59a0aa5009d27.png Homework Equations Kirchhoff's Current and Voltage Laws, Resistors in parallel and in Series. The Attempt at a Solution The main thing confusing me is the diagonal 6 Ohms, not too sure what it is parallel too and how...

so i need to reduce a dc 12v to dc 5v. do you know what type of resistor i should use? also could you please suggest an online calculator or an equation so that i can find the resistance i need in the future.

< Mentor Note -- thread moved to HH from the technical forums, so no HH Template is shown >[/color] https://drive.google.com/file/d/0B3gxtQyBRFkLQU9YdExMaTczTEk/view?usp=docslist_api Here is the copy of the circuit I am try to anaylze. I come up with three amps, but the answer book says .75...

Homework Statement Homework EquationsThe Attempt at a Solution I have selected what I thought were the right choices in the original question. Resistors reduce current so electron flow should have been greater on the right. Also, the electrons flow opposite to current so potential is higher...

What's up people? I'm new in this wonderful forum. I have several questions about circuits, and they are not really common, I mean, I find them somehow complicated, but I would really come to enlightenment if you guys gave me some clues. 1.- So, let's suppose we got the simplest circuit, a...

Homework Statement 1. Find the power dissipated by 12 ohm resistor 2. What is the potential at points a,b,c,d? Homework Equations P=I^2R I=V/R The Attempt at a Solution For a) 3v-IR-6v-IR=0 9v=I(18) I=0.5 P=0.5^2 * 12 = 3 watts But not sure if the ground changes anything b) unsure if ground...

I'm extreeeeamly rusty at basic circuit theory. I want to transform a sort of infinite arrangement of this circuit: The values themselves aren't important, just the representation of what's happening, all the verticle resistors are the same value as each other, and all the horizontal resistors...

Homework Statement A 10 ohms resistor, a 12 microFarad capacitor and a 28 mH inductor are connected in series with a 170 V generator. A.) At what frequency is the rms current maximum? B.) What is the maximum value of the rms current? Homework Equations A.) Fo = 1 / 2pi sqrtLC b.) Irms = Vrms...

I read that the memristor is described by the equation dφ=Mdq. If both sides are divided by dt, then dφ/dt=Mdq/dt. But dφ/dt=V and dq/dt=I. Then V=MI which is ohm's law. Isn't the constant M just the same as resistance?

Hi, I am working on CdZnTe detector. Can anyone please explain the function of bias resistor in radiation detector setup & how to select an appropriate bias resistor?

Hello, my motherboard recently has stopped working, so I returned it to warrany, they fixed it, but after a few months the board broke again, but unfortunatly the warranty has ran out, so I'm attempting to fix it myself in the freetime :D So I have found a resistor on the motherboard, that looks...

In a simple circuit are there any charges accumulated at two ends of resistor? There is an conservative and thus electrostatic electric field and potential difference across the resistor. It seems it is only possible if positive and negative charges are accumulated at two ends to provide the...

See photo! Why does the power dissipated increase and then decrease (see graph)? Is it something to do with emf? Also can internal resistance change as the variable resistor increases/decreases or is it always constant? - this isn't one of the questions they ask I'm just wondering

If your doing an experiment to test how the temperature affects a thermistor (increase temp measure v and I...) why do you need a variable resistor in your circuit? Or if you don't NEED one what beneficial use may it pose anyway? Is it something to do with the current? Thanks

Homework Statement The resistor R in the above figure has a resistance of 19.1 Ω. a. Find the current in the resistor R. b. Find the current in the 10-Ω resistor. 2. Homework Equations Kirchhoff's Laws (Junction Rule and Loop Rule) V=IR The Attempt at a Solution I figured out part a (I...

The following circuit is a Vbe temp compensated circuit Query : what exactly the use of the 10k resistor required to connect the bases of two transistors...we can also have a direct coupling to connect the bases of both transistors...what exactly the difference it could make by adding the...

Could you solve this?

Homework Statement For some applications, it is important that the value of a resistance not change with temperature. For example, suppose you made a resistor from a carbon resistor and a Nichrome wire-wound resistor connected together so the total resistance RT is the sum of their separate...

The cell can provide conatant emf ε and initial charge of capacitor is zero. Now current through resistor initially is zero and increases. But the potential difference across the capacitor is always a constant with magnitude ε. then ##\frac{q(t)}{C}=E## So ##q(t)=CE## which implies q is constant...

Homework Statement Part (a) has already been solved and determined to be 5kΩ, which has been confirmed by the answer key. The answer key also states that the maximum power able to be delivered to Ro is 957 µW, but doesn't give any workings or explanations on how to reach this answer...