Resistor Definition and 894 Threads

Homework Statement Thermal energy is to be generated in a 0.31 resistor at the rate of 11 W by connecting the resistor to a battery whose emf is 2.1 V. (a) What potential difference must exist across the resistor? (b) What must be the internal resistance of the battery...

Homework Statement In the pictured, the battery puts out 12 volts, R1 is 9 ohms, R2 is 6 ohms, and R3 is 5 ohms. What current flows through resistor R1? Please use only SI (metric) system units in your answer! Homework Equations R=V/I ? The Attempt at a Solution I am...

I am confused on a question that arises in my mind: that is "After passing the resistor the amount of current flowing through cross section of area is decrease or the energy of charges i.e Potential decreases".

I need some help identifying what I'm pretty sure is a resistor. I have a power supply that blew up, I opened it up and everything looks ok except for this. The color bands are: Brown Blue Silver Gold Black The only problem is that silver isn't a valid color for the third...

Homework Statement I'm confused because in my textbook, it says that when R is large, there is very little current and if it is small, there is more current through it when there's a potential difference across the resistor...but like in another book, it says that current is not used up when...

1. What is the current through each resistor 2. All the obvious stuff... 3. Ok, without showing all my work, here's what I have solved and know is right: The equivalent resistance of the whole circuit is 56.3 ohm. From this, I used Ohm's law to get the equivalent current for...

Homework Statement A variable resistor, R, is connected to the terminals of a battery (dashed box in the diagram). The graph below shows data collected in the circuit as R is varied. What is V0, in volts? What is the internal resistance, r, in ohms? should the V0 be measured at the top...

Homework Statement Five resistors with resistance R1 = 4.90 Ω, R2 = 7.30 Ω, R3 = 8.80 Ω, R4 = 2.70 Ω, R5 = 5.00 Ω, are connected to a battery with emf E = 8 V in the circuit shown. What is the current in resistor R1? I also need the current through all other resistors. I know you need to use...

Homework Statement The heating resistor is rated at 10ohms and 1W. By how much was its power exceeded? Why didn't the resistor burn up? This is a question taken from an Electrical Equivalent of Heat lab assignment... here is a link to the exact same lab we did...

Circuit: Here's the circuit: there is a 8V battery. The charge leaving it reaches a junction: if the current "turns right" it goes to a 12 ohm resistor (R1) and can then loop around back to the battery, if it goes straight (i.e. takes other path at junction) it runs into a 4 ohm resistor (R2)...

http://www.webassign.net/tipler/26-50.gif I presume the 4 ohm resistor is parallel with the diagonal 2 ohm. It's equivalence is parallel to the vertical 2 ohm. Then, the result is in series with the 3 ohm. I then substituted values in V=IR and worked backwards to find the current and...

1. The 10 ohm resistor in the figure is dissipating 40W of power. How much power is the 5ohm resistor dissipating? 2. P = I2*R 3. I = sqrt(P/R) = 2. I then did P = I2R = (4)(5) = 20 which is incorrect.

Hi experts, i am wondering if i want to have a few ohms of resistance but does not have any resistor and i use coil a wire that produce a resistance of a few ohms, how different is this 'resistance' compared to the resistance from a resistor of the same ohm value ? I know that a coil produces...

if my 12v motor draws 10amp when running am i right to think if i put 6v on the same motor it will run at half speed? how would i work out the resistor needed to do it? i think i need to be using ohm's law somehow but can't remember just how,its been a while since I've needed to do something...

Homework Statement I understand the maths... I'm here to ask WHY we have to do it this way. The question states: "The power dissipated in a resistor is given by P= E^2/R. If E=200 and R=8 , find the change in P resulting in a drop of 5 Volts in E and an increase of 0.2 Ohms in...

I searched practically all of the nets and webs and still my questions are unanswered, so I decided to consult y'all. I have previously asked you guys about diode sizing to prevent back emf on a relay and you were very helpful. I am once again calling upon your help. I have some relays in my...

Hey, so I have this loop circuit that has some input voltage V in series with a resistor with a resistance of R and another in series resistor that is my load resistance, let's call it G. V and R are not variables, only G is. I know that because of Jacobi's law, to maximize the power...

Consider this circuit with R1 = 30 ohm, R2 = 10 ohm, R3 = 10 ohm, R4 = 20 ohm, R5 = 60 ohm. (the circuit is attached) A. What is the current across the resistor R2, if a voltage of 110 Volt is applied to the two terminals at the bottom of the figure? B. What is the voltage drop across R2...

I am having problems understanding how a resistor resists or limits current flow (or electron flow). http://img714.imageshack.us/img714/5595/currentquestionimage.jpg In circuit 1, if I understand correctly the current at Point 1, Point 2 and Point 3 are all the same – that is if you...

1. If I know the voltages on both immediate sides of a resistor...lets say v1 is on voltage on left side of resistor, and v2 is voltage on the right side of the resistor, is the votage of the resistor = v2 - v1 if the positive side of resistor is to the right? Or can you not even calclulate the...

If I know the voltages on both immediate sides of a resistor...lets say v1 is on voltage on left side of resistor, and v2 is voltage on the right side of the resistor, is the votage of the resistor = v2 - v1 if the positive side of resistor is to the right? Or can you not even calclulate the...

Homework Statement Find current flowing through each resister, voltage across each resister and power consumed by each element in the following circuit. See the attachment Homework Equations The Attempt at a Solution The question I want to ask here is that is the current...

Hi, will I damage the IC (it is 74LS07) if I select a pullup giving 20 mA of current trough the open collector (without any other load)? I looked at the datasheet but I can't figure which parameter should I be looking at (because they give HIGH-level output current of 250 micro amps. What I...

In an alarm clock, there needs to be a delay of 1 minute between closing switch and circuit being active. A 2200microF capacitor is charged through a resistor from a 5V supply. The pd across capictor must rise to 4.3V for alarm to become active. Calculate size of resistor. The answer is...

Hi, I am going through some texts but it was not very clear.I hope some experts here can help me on this. The max voltage across the relay and stabilising resistor is given by; (If/N)(Rs+Rb) where If - max short circuit rating, A N - current transformer, CT ratio Rs - CT internal...

Hi guys, I was reading about monte carlo analysis in the introduction from a textbook, and they gave an example of a voltage divider. They assumed resistor values had an equal probability of having values between the two tolerances. I know this is a simplistic assumption and I was wondering...

I am looking for a resistor that can dissipate a constant amount of heat at all temperatures immediately. I have been using some metal film/oxide resistors, but it takes a very long time before the resistor starts radiating heat. I think the material making up the resistor has such a high...

Hey again. I have a circuit that I've made and I was told I should put resistors in so that I don't blow out my transistors and buttons. Ok, I can do that... but I have no idea what size of resistor I need! Picture: I'm using TIP41C Transistors: http://www.drixsemi.com/TIP41C.PDF...

I have a tiny bit of current fluctuation on one of my lines. If i put a lil 500ohm resistor in the line the osillations on the other end substantially decrease. Why? Does the resistor effectively 'absorb' these oscillations?

I posted this question in the physics forum with no luck, the concept has to do with physics but it's applications is within the body. It is found in the lung and also in venous return curves, when central venous pressure drops below 0. Basically, I am asking how the concept of zone 2 in the...

In my home I am getting 220 AC Volts of electricity. I want to connect white color Light Emitting Diod (LED) that requires 3 volts output with the resistor which will be connected to 220 Volts power. So can anybody please tell me what is the formula to find that how much voltage is output from a...

Homework Statement In the circuit the emf is 150V connected across a resistance network. Each resistor has a value of 10 ohms. What is the current through R2? Homework Equations R=V/I The Attempt at a Solution I found that the resistance of R2 and R3 because they're in a series is...

My question is in regards to a starling resistor. A starling resistor is where a flexible tube passes through a box that can have it's pressure changed. If fluid passes through the tube then flow through the box will be determined by the pressure differences from the two sides of the box...

Is a Light Dependent Resistor (LDR) resistant to water? Will there be any problems if it is exposed to water directly?

Homework Statement What direct current will produce the same amount of thermal energy, in a particular resistor, as an alternating current that has a maximum value of 2.60 A? Homework Equations The Attempt at a Solution A DC would dissipate a constant amount of thermal energy in a...

Homework Statement (a) For the circuit below, the value of R is adjusted so that each of the two 10Ω resistors dissipates 10W. Calculate the value of the variable resistor R. (b) What is the value of R if it is adjusted to dissipate the maximum power possible? For this value of R...

Hello Everyone, I was spending some time today organizing my resistor collection into drawers when this nagging question came to mind. How did they come up with the standard resistor values that we have now? There must have been some kind of rationale to it as one would normally expect the...

A resistor draws a current i=8sinwt at a voltage of v=200sinwt. Calculate the average power dissipated in the resistor. What i did is p=ui = 1600sin^2 (wt) and i got stuck:P i don't think it's the right equation.. the answer should be 800W .. and that's nothing like it. Could someone help me ?

Homework Statement Consider the resistor network shown in the figure below, where R1= 5\Omega and R2= 7\Omega . (a) Find the equivalent resistance between points a and b Req=([1/6 +1/5]+7)+12+6=(9.73)-1+18-1=6.32\Omega (b) If the potential drop between a and b is 12 V, find the...

Homework Statement In the circuit of figure p28.23, determine the current in each resistor and the potential difference across the 200 ohms resistor. http://s848.photobucket.com/albums/ab41/tag16/?action=view&current=circuit.jpg&newest=1 Homework Equations 1/Req= 1/R1+1/R2+1/R3+1/R4...

I want to find the increase in the temperature of a resistor due to joule heating. I mean that if we apply some electrical power to a resistor then the electrical energy is converted to heat energy due to joule heating. The heat energy will increase the temperature of the resistor. Is it...

Hello Forum , I would like to ask you about the resistor value ideal for a laser module 3V @45mA and the power supply is 3.3V , R= (3.3-3)/45= 6.6 ohm ? it sounds a little strange to me. Have a nice day and thank you in advance.

If a resistor is connected parallel to a straight wire joining the two terminals of a battery, does any current pass through the resistor. Is there any current in the circuit?

Homework Statement hi guys, i'm having trouble applying Kirchhoff's laws to determine the equivalent resistance of this symmetrical array of resistors (see attachment); i think there is a quick trick, using 4 current loops, but i can't remember it... nor find relevant documentation – this is...

Circut help! Homework Statement In the circuit shown below, the batteries have negligible internal resistance. (a) Find the magnitude of the current in each resistor. I3 = ?? A I4 = ?? A I6 = ?? A Homework Equations V=IR i don't know where...

Homework Statement In the circuit shown, the same current must flow through all three componets as a result of conservation laws. Using the fact that the total power supplied equal the total power absorbed, show that the voltage across resistor R2 is given by: v_{R_{2}} =...

http://img5.imageshack.us/img5/6889/imagepf.jpg I need to create a formula using R (resistance), U1 and U2 (voltage) for the current flowing through the 8 Ohm resistor. I've been looking at this for hours now and I still don't even know where to begin. Can anyone get me started on this?

Homework Statement http://dl.getdropbox.com/u/119186/Picture%201.png Homework Equations I = I2+I3 I= e/R The Attempt at a Solution http://dl.getdropbox.com/u/119186/snapshot-1253898419.920882.jpg As you can see I got all of it, but part C. I can't figure out what the process...

I'm designing a circuit for experimental use. I'll make this as quick as possible. Browsing other circuit designs on the web, I initially noticed "followers" placed between other op-amp app's (adders, integrators, inverters, etc). From what I can tell, putting in followers like this must be...

I am trying to determine ohms and wattage of R2 on attached schematic. The resistor fried so I can't tell anything about it This circuit is a recharger for a cordless black and decker drill Thanks