Currents Definition and 497 Threads

Homework Statement A circular loop of wire and a long, straight wire carry currents of I1 and I2 (see the drawing), where I2 = 5.2I1. The loop and the straight wire lie in the same plane. The net magnetic field at the center of the loop is zero. Find the distance H, expressing your answer in...

someone knows how eddy currents in transformers are produced? by friction , resistance or heat transfer? i mean the classical example is the wheel that is braked between the poles of an electromagnet, but how this applies to a transformer where there is exactly the opossed, a fixed conductor...

Question: 1. a) what is the force per meter on a wire carrying a 9.80-A current when perpendicular to a 0.80-T magnetic field? b) What if the angle between the wire and the field is 45°? For part a) I know that F = ILB, where I is the current, L is the length of the wire and B is the size of...

A circular loop of wire and a long, straight wire carry currents of I1 and I2 (see the drawing), where I2 = 4.9I1. The loop and the straight wire lie in the same plane. The net magnetic field at the center of the loop is zero. Find the distance H, expressing your answer in terms of R, the radius...

Please help me if you can... question: Use the following quantities to calculate the magnetic field strength of the horseshoe magnet. Mass of coil: 20 grams current in coil: 2.0 amps length of bottom of coil: 10cm angle coil makes with vertical: 30 degrees Hint: Equate magnetic...

Something I keep on wondering about - wouldn't currents have some inertia, some tendency to keep on moving, even if there is no inductance? After all, electrons have inertia and they would tend to keep on moving in the same direction even when there's no electric field pushing them ... Is...

A 23 V battery is connected to terminals A and B below. (a) If R = 95 Ω, find the current in each resistor (/12, /55, /95). (b) Suppose the value of R is increased. For the 12 Ω resistor, does the current flowing through it increase or decrease? What about the 55 Ω resistor? What about...

http://img335.imageshack.us/img335/8383/physics4a8ua.th.png http://img335.imageshack.us/img335/8000/physics4b6vo.th.png "Find the currents in the circuit branches in [the first figure on the left above]." V1 = 20V, V2 = 10V, R1 = 5.0 ohms, R2 = 4.0 ohms, R3 = 6.0 ohms, R4=R5=R6= 2.0 ohms...

9 - 2.7(I) - .038(I) = 0 13 - .023(I) + 2.7(I) - 9 = 0 I don't know how the dead battery effects it and how to figure out the different currents thru the different resistors

I'm having trouble with curcuits, my first problem is that I'm not sure if this is a combination parallel-series curcuit? For the simple circuit (attached diagram) determine the current through each resistor and the potential difference at the 5 ohm resistor. I think that the 2 ohm...

Another Electromagnetics question... Two long wires carry equal, but oppositely directed, 25 A currents. What is the magnitude of magnetic field due to these currents at point P? The wires are 0.1 m apart and point P is 0.05m in between the wires. Would the following be the correct way to...

Gents, Is it possible to have the not singular chiral current (singularity is due to the product of fermionic operators) and at the same time the translational invariance. Normaly to get rid of singularity in chiral current one is useing the point splitting regularisation (little shift of...

I came across the following problem recently: http://www.tubaroo.com/stuff/circuit.gif R_1 = R_2 = 4700 \Omega C = 0.060 F V = 12 VS1 has been closed for a long time. At t = 0, S2 is closed. Sketch a graph of the currents I_1 through R_1 and I_2 through R_2. I wasn't really sure where to...

HELP ME PLEASE! Given B=0.80 T, a square coil with a single loop with length of each side of 20 cm, a current of 5.0 A where there is an external constant uniform magnetic field, what are the size and the direction of the magnetic force on just the lower section of the loop due to the 0.80 T...

Hi all, I only have a real basic knowledge of quantum mechanics and I am finding a paper that I am taking quite challenging. If it is possible for someone to give me a hint or starting point on this folowing problem that would be great. For problem - see attachment Thanks.

I have to list the temperature (cold or warm, the black ones "are the same temperature as the current leading into it") of the following currents: North Atlantic Labrador (Newfoundland) Oyashio (Japan) Alaska California Gulf Stream Canary (NWAfrica) Kuroshio (Taiwan) Peru...

Dear Gents, I have one question: Can I say that if I I have some currents, charges form these currents (integrals over time components) and these charges form a close algebra of some group SU (N), then I say that the particles sitting in these currents (all possible incoming/outgoing...

Help - Loops Currents. :( hey there I'm revising for an exam and i can't really do loop currents i was trying to do this sum http://mathonweb.com/help/backgd4.htm (example2) but kept getting the rong sign for equations (for shared resistors):( could someone please explain to me! thanx in...

This problem doens't seem hard, but I am rusty on the right hand rule... Four electric currents, equal in magnitude are arranged at the corners of a square as shown in the figure. http://img368.imageshack.us/img368/2654/fourcurrents7jc.jpg Two currents go into the page (marked by x), and two...

I have been taught that the voltage in a capacitor and the current in an inductor cannot change instanteously. This is important especially when solving differential equations for a circuit network. Can someone explain to me why these events cannot happen? To the extent of my knowledge for these...

Hello, I've just entered this forum and... the world of Physics. And I already have tremendous enigmas. Let's start with this. Oersted revealed that a static magnetic field exists in the nearby of a current loop. Now "current" means "moving electric charges" and e.m. theory states that a moving...

Consider the following problem: There is a uniform magnetic field pointing into the page. A set of rails is placed horizontally inside the field. A metal rod can slide freely on the rails, when we apply a force to move the rod to the right, is there any induced current in the rod when moving...

Hey, I have a question to ask and was wondering if you guys could help me. 5.) A computer has a 300-W power supply. If household voltage is 120 V, how much current will flow through the computer? A. 0.4 A B. 2.5 A C. 180 A D. 420 A E. 36,000 A I picked B. I used the equation...

Four very long, current-carrying wires in the same plane intersect to form a square with side lengths of 42.0 cm , as shown in the figure. The currents running through the wires are 8.0 A, 20.0 A, 10.0 A, and I. ******^ ****** | ------10 A------I -------|--------|-------- 8 A --->...

1] Two long straight parallel conductors each carrying a current of 24 amps flowing in the same direction are fixed at a distance of 40mm from each other. A third parallel conductor is placed equidistant from the other two and carries a current of 30 amps. Show that the force on the third...

I have to find the Requivalent and all of the currents and voltages in the circuit below. l------------Resistor 1----l---------l l l l battery l l l Resistor 2 Resistor 3...

What is the maximum instantaneous power dissipated by, and maximum current passing through, a 3.0-hp pump connected to a 240-V ac power source? ANSWER: 6 hp, 13 A Given: P = 3 hp = 2238 W (1 hp = 246 W) V = 240 V I don't know which formula to use. At first, I attempted to use P...

So this problem asks you to determine the magnitudes and irections of the currents in the resistors. I definitely understand how to determine directions, using Kirchhoff's Rules. But here is where I get stuck: the batteries have emfs of E1 = 9.0 V and E2 = 12.0 V and the resistors have vlaues...

Two long parallel wires are a distance of d = 4.5 cm apart and carry equal antiparallel currents of 1 Amperes. Find the magnetic field intensity (in T) at the point P which is equidistant from the wires. (R = 2 cm). Now I really thought I had this. I thought the magnetic field at P would...

Anybody Know The Currents And Equations For This Problem? Please if you can, help me! I am usually very good at circuit problems but this one has me baffled! here's the link: http://www.coloradoacademy.org/~phogan/apphys/quiz/rq2_8b.htm Thanks A Lot!

I'm kinda stuck on this question: 1. Calculate the magnitude ofthe magnetic f ield at a point midway between two long, parallel wires that are 1 .0 m apar t and have currents of1 0.0 A and 20.0 A, respectively, ifthe currents are (a) in opposite directions and (b) in the same direction...

http://www.nature.com/news/2004/041025/full/041025-9.html Great! Wait until the extreme sports folks get ahold of this one. :biggrin:

I am working on a project involving electrically heating clayey soils (having 55% moisture content and 0.5 M salt (nacl/KCl) solutions in the pore space. Does anybody know if electrolysis of water/electrolyte is a concern with AC currents (230 V, 60 Hz frequencies)? Thanks, WWW :smile:

Do convection currents occur in all bodys of water and gas? Or are they only at a certain temperature, under certain circumstances?

If we imagine a fluid traveling through a pipe as being a warm current of sea-water moving over a cold denser layer of sea-water, with the air immediately above the warm current forming one wall of the pipe, would the pressure of the warm current decrease as the current travels faster,and if...

I've read that when currents in two parallel wires are going in the same direction, they attract each other. The same text said that when the currents are going in opposite directions, the two wires repel each other. Why does this happen? Is there a different behavior for AC and DC currents?

I have the following problem on which I am unsure how to proceed. A spring with a spring constant K = 20 N/m is shown below. It is stretched 1 cm from its equilibrium position when a current I passes through the wire. How big is the current in the wire? The magnetic field is coming out...

Hey there! This question has be a bit confused as to where to start--- Suppose you made a 4.70 k-Ohm resistor from a carbon resistor and a Nichrome wire wound resistor connected together so the total resistance is the sum of their separate resistances. What value should each of these...

Hey - do you think anyone could help explaining the process of conduction and radiation, convection currents for me? Physics exam next Monday, and I have to start studying soon! Also, what is density measured in? Kg/M^2? Thanks in advance!

A high voltage transmission line with a resistance of 0.06 ohms/km carries a current of 1337A. The line is at a potential of 500kV at the power station and carries the current to a city lovated 191km from the power station. What is teh power loss due to resistance in the line? Answer in units...

Our physics teacher gaves us online homework, and he was gone on friday and it is due by midnight tonight. Here is an example problem that we are having trouble with: A copper cable is designed to carry a current of 400A with a power loss of 4 W/m. What is the required radius of this cable?

The emitter current in a certian npn transitor is 8 mA. If .8% of the minority carrier injected into the base recombing with the holes, find the base current , collector current and the exact value of alpha i am not sure how to get this started thanks joe

At my school we are currently investigating Currents & Electricity and me and my teacher would like to know why Current was giving the symbol 'I' instead of say 'C' more so when Volts is given 'V' and Amps is giving 'A'. Both of us would really like someone to shed some light onto this matter.

I have a CRT monitor aligned against the wall of my apartment. At times the screen begins to shake as though a current was running near it. I looked outside and there are 3 big 1-1.5 inch thick wires going up the wall near where my CRT monitor is. I assume this is the problem. Because of my...

i have been following the posts about the electric sun my interest is the birkeland currents, this link gives some insight http://www-istp.gsfc.nasa.gov/Education/wcurrent.html my problem is understanding how these currents flow through space "how is the initial contact made"? why is it...

I am trying to add an LED to one of my computer parts, but there is not enough current flowing through. I would like to know how to increase the voltage to the LED without messing with any computer parts. I remember something about wires, but i do not remember exactly what to do to increase...

Guys & Gals Everyone has seen the jumping rings demonstration…. Aluminium works fine, so does silver, iron and steel just stick to the coil Cut slots or drill holes in the disks and you get what you would expect BUT… Why doesn’t gold work? Cheers Mike