Resistor Definition and 879 Threads

A o.3micro farad capacitor is connected across a 15V, variable frequency ac power supply. Find the current in the circuit when the frequency is a) 100herts (b) 100kilohertz c) solve this question if thee 0.3 microfarad capacitor is replaced by a 40 ohm resistor. My solution I = wCV a)...

Homework Statement The drawing shows a wire loop near a current -carrying wire. Under what conditions would current flow through resistor R from Right to left? Homework Equations Lenz's law The Attempt at a Solution 4 answers a) when the current I is increasing b)when the...

Homework Statement What value of \omega will cause the forced response v_0 in the circuit below to be zero? http://img248.imageshack.us/img248/1854/problem934ao5.jpg Homework Equations Phasor eqs. The Attempt at a Solution...

Special lamps may be purchased to help plants grow indoors. These lamps produce light with wavelengths comparable to natural sunlight. A manufacturer wishes to check these lamps by measuring the out put of the lamp at different wavelengths. The above is the scenario given :smile: You are...

I've no idea how to start the following question so any help or guidance would be really appreciated. A potential divider circuit is set up with a LDR and a fixed resistor, R. The LDR has a resistance of 200 Ω when it is light and 2500 Ω when it is dark. A motor is set so that it comes on if...

Homework Statement A 10-ohm resistor has a constant current. If 1200 C of charge flow through it in 4 minutes what is the value of the current? A) 3.0 A B) 5.0 A C) 11 A D) 15 A E) 20 A The Attempt at a Solution I get B as an answer. I=(Q/t). I= 1200C/ (4 * 60) = 5.0 A The book...

Lenz's and Faraday's Law Induction. Help on resistor and switches! Homework Statement Find the direction of the current in the resistor shown below a) at the instant the switch is closed b) after the switch has been closed for several minutes and c) at the instant the switch is opened...

Need some help finding the value of the input Resister... Design a 7.5V zener regulator circuit using a 7.5 zener specified at 12 mA. The zener has an incremental resistance of 30 ohms and knee current of .5 mA. The regulator operates from a 10 V supply and has a 1.2 k-ohm load. What is the...

Homework Statement In a circuit a 20-ohm resistor sits inside 104 g of pure water that is surrounded by insulating Styrofoam, there are additional resistors in the circuit. If the water is initially at temperature 10.5 degrees celcius, how long will it take for its temperature to rise to...

How to calculate current of a resistor "inside" of another parallel resistor? The 1st image is how he drew it for us, no text.. I guess because it's quite complicated. He asks a bunch of questions, I've answered.. 1. Equivalent resistance of R3 and R4=5 ohms 2. combined resistance of R6 and...

2 series resistors are in parallel with another resistor.. Homework Statement Resistors R1, R2, R3 have resistances of 15ohms, 9, 8.. R1 and R2 are in series and the combination is in parallel with R3 to form the load across a 12 volt battery. a)diagram b)total current c)Current across R3...

Homework Statement A scheme of a diode circuit is attached. The voltages at the inputs A and B are 5V. A. What is the output voltage (=voltage at the black node, Z)? B. What values of resistance would you recommend for the resistor R? 2. The attempt at a solution A. The diodes D1 and...

Hi! What would happen if the resistor in the attached diode OR gate removed (connection with the ground would be preserved)?

Homework Statement A parallel-plate capacitor with cross-sectional area S and plate separation d is put into a stream of conducting liquid with resistivity \rho. The liquid moves parallel to the plates with a constant velocity v, and the whole system is located in a uniform magnetic field of...

Homework Statement The currents are flowing in the direction indicated by the arrows. A negative current denotes flow opposite to the direction of the arrow. Asume the batteries have zero internal resistance. Find (part 1)the current through the 5.3 ohm resistor and the 3.1 V battery at the...

Homework Statement In the circuit below: (a) Find the current I1 that passes through the 7.5 Ω resistor. Homework Equations Kirchhoff's Rule--Loops The Attempt at a Solution This was a problem in my textbook. The answer is .65 A, but I don't understand how to get that. I tried...

From a mathematic, linear differential equation point of view, and energy storage point of view, the concepts I mentioned in the topics are the same (I remember this being a concept in modeling control systems.) My question is, what are the same basic elements in other topics: thermal...

Hi frnds Iam working on an investigatory project wherein iam studying the variation of resistance of an LDR with intensity of radiation and frequency. Regarding the frequency dependence iam having a doubt as the results tht I've got arent consistent. Could anyone guide me... whether...

hello, I am new here.. so please excuse my..um. n00bishness im sorry if this under the wrong area, i doint know which area of physics it might be under, i just remember reading about resistors back in HS physics...which was years ago.. I'm currently building a shed lighting system through the...

Here's what I know: A 1.89 nF capacitor with an initial charge of 5.26 mC is discharged through a 1.34 kW resistor. I'm supposed to find the maximum current in the resistor. I know the maximum current through the resistor is -2.077 A from the equation I(t) = -(Q/RC)*e^(-t/RC) and I know...

my question is that i have two resistors that are combined to form an equivalent resistance of 1000 ohms. Now there are two common resistors rated at 500 plus/minus 50 ohms and two others rated at 2000 ohms plus/minus 5%. I need to know what combo (series or parallel) would provide the smaller...

A resistor network is built up indefinitely as shown in the figure. The equivalent resistance across AB is A. 1 ohm B. 1.24 ohm C. 2 ohm D. unable to be determined. -> I don't know where to start with. Can anyone give me some hints?

A resistor with a resistance of 500 ohms and a capacitor with with a capacitance of 2 x 10^-6 f are connected in parrallel to an ac generator that supplies an rms voltage of 260 v at an angular frequency of 377 rad /s find the current amplitude in the resistor (Ir)peak. I know I have to...

Today in physics lecture our physics teacher left us with a riddle. If you had an infinite grid of resistors say with 1 ohm of resistance set up between every node of the grid and then you connected a battery that supplies a current of one amp through across a single resistor, what would be...

I have a circuit with a capacitor, resistor, and inductor all in parallel with each other. I have to write the differential equation governing the voltage. However, when I attempt to do that [using Kirchoff's Voltage Rule] I will end up with: Vc + Vl = 0 and Vl + Vr = 0 However, this implies...

Hey, I'm having a bit of difficulty with this one. I spoke to my professor specifically about this problem, he worked through it, I understood him, and I worked through it later in the day. I still get it, I worked through it, and there's step at the end that we both did differently. It seems...

this isn't so much of a homework question . I am having trouble with identifying and calcultaing effective resistence for parallel or series connected resistors particularly ones that are very complex to even understand what's going on ... I did look through various websites and books looking...

Hello, Is there a way to determine the tolerance of a surface mount resistor by its markings or coloration?

three resistors that have values of 5,2,1 ohms, are connected in series and parallel to a battery, which resistor gets most power in both series and parallel?

The aorta branches into up to 30-40 billion capillary vessels, 8-10 billion of which are used effectively. As a consequence the cross-sectional area increases by a factor of 800. If we start from the assumption that there are 9 billion capillary vessels (all of which are equally thick) – how...

im given a a 20-mH inductor and a 30 ohm resistor in parallel. Z_in is 25 degrees. and I am asked to find the frequency omega in rad/s here's what i try to do: 25=(jw.02*30)/(jw.02+30), and solve for w, but i don't get the right answer. what is it that I am doing wrong?

I am looking for a low resistance resistor to put in my circuit to lower the current slightly. My circuit is/will be running off a 12 power supply and normally will draw somewhere between 11 and 13 amps under normal operation. I would like to add in an additional maybe .5 to 1 ohm resistor so...

Pls help.. If i have a capacitor of capacitance 3uF connected in series with a resistor, what will the potential difference across the 1ohm resistor when the EMF is 6V? Is the answer a zero? If yes, why? is it becoz the capacitor itself have make the circuit a open circuit such that no...

im stuck on this question and was wondering if anyone could help point me in the right direction: a half wave rectified voltage is described by: v(t)=100.sinX (that X is mean to be theta) when applied to a 50 ohm resistor find the average and rms values of the current. thanks an help is...

I would like to find the transconductance of such circuit. I am choosing to ignore r_0 for the time being and going with the definition G_m = \frac {i_0}{v_i} \bigg |_{v_i = 0}, What I did first was notice that i_0= - g_m v_\pi[/itex] v_i appears as the top node voltage at r_\pi w.r.t to...

I have to solve this problem for a circuit. Its a capacitor, a resistor and another capacitor all in series. Both capacitances are the same, 1uF, and the resistor is 100k-Ohm. I have to find the current function of time. What I did was use KVL to get: - \frac{1}{c_1} \int i(t)dt...

Sorry, no picture my bad. Here is the circuit, everything is in PARALLEL, First its a 1mA source, then its a switch, then its a resistor of 10k-ohm then its a capacitor 1uF. Sorta like below: ---------------------------------- | ...| .... |.... | O...Switch ... R ... C |....|...

Four circuit elements—a capacitor, an inductor, a resistor, and an AC source—are connected together in various ways. First the capacitor is connected to the source, and the rms current is found to be 25.1 mA. The capacitor is disconnected and discharged, and then connected in series with the...

I have conducted an experiment in school I have some problem with it . I connect a resistor 6600 ohm to a 6V direct current and I read the miliammeter and it show about 0.9 mA . But after I connect a capacitor 3300 F parallel to the resistor , the miliammeter increase to more than 1 mA.Why the...

v(rt) = 125mV cos (wt + 60) R=250 ohms L = 250mH find i(t) in the circuit there is a inductor in series wif the resistor the answers i(t)=0.5 cos (wt+60) may i know why is it the inductor not using to form z and then only divide by v(rt) ??why only the resistor??

I have a 12V power source in a circuit and 4 resistors in a line and 1 on the side how do i find the voltage across each resistor?:confused:

can any1 clue me into how u calculate the current through a resistor and the power absorbed by a resistor please!?

Can someone tell me where I'm going wrong here? I'm uploading a jpeg of the circuit, I'm supposed to find the equivalent resistance between A and B. To me, it looks like R5 and R6 are in parallel and forming Rp56. From there I'm assuming that Rp56 would be in parallel with R3 and then that...

Here is the diagram and work the answer booklet says: http://img69.imageshack.us/img69/2593/untitled1copy7wg.jpg Okay first question, If you loook on the image and look at the Current Source Is, the arrow shows its going up and to the left, so that means its going to go through the 2.5 OHM...

Hello everyone I have a slight problem. I am confused on how you know what path current is going to travel and also what voltage sources your suppose to add up to a specific resistor. For example here is my picture, already solved: The directions where to find the value of ix, the orignal...

Hello every9one I'm stuck on finding the first part: A series RLC circuit is driven by an alternating source at a frequency of 380 Hz and an emf amplitude of 90.0 V. The resistance is 20.0 , the capacitance is 12.1 µF, and the inductance is 24.2 mH. What is the rms potential difference...

Why would a circuit have a zero ohm resistor (3 black bands) in it?

for the question: the toal voltage across a string of seires resistors is 24V. If one of the resitors is open, how much voltage is there across it? How much is there across each of the good resitors? my problem: isn't it impossible to find which part is open in a series circuit without...

The statement, "when a resistor fails, it will normally open." is true. But I don't understand: when a resistor fails, doesn't that mean that the resistor doesn't work? so doesn't that mean that resistance=0=short circuit?

SEE POST 4 I am having problems solving these resistor problems and was wondering if anyone could help. Really what I think my problem is is that i don't know what to do if there are series and parallel resistors on the same circuit For attachment three The resistance of the...