Ohm's law Definition and 183 Threads

Dear Friends I just want to know how to prove ohm's law...need your help... Thank you

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...

Dear Fellows I have just came across with the basics of electromagnetism, and about the application of electric and magnetic force on charge particle, Ohm's law for charge is j=σE (1) if the charge is moving with the...

I have some problem understanding the concept of the voltage changing across a resistor. Given V=IR (Ohm's Law) Ok so according to Ohm's Law, if I increase the resistance of a circuit, the potential difference of across the resistor will change. I know that potential difference is...

Homework Statement (i) Using Ohm’s Law, determine the equivalent resistance across the battery (I think I've worked this out but am not sure I'm right) (ii) Determine all the currents flowing in the circuit (I'm unsure how to get his?) Homework Equations Ohms Law The Attempt at a...

Hopefully this is a simple question. When a potential difference is applied, do charged particles begin to accelerate and then reach a terminal speed due to resistance where resistance would have to be proportional to that speed? In other words, if there was this magical material with zero...

Homework Statement Hello guys. I've ran into this conceptual problem. I was given into physic's lab to prove Ohm's law by mounting a circuit in two ways, and calculate both Voltage and Intensity. The first circuit, the A (Please refer to Circuit A.jpg), has the inconvenient in which the...

I have trouble understanding how the following experiment tests Ohm's Law. Imagine a simple DC circuit with a 6V battery connected to a resistance that is in parallel with a voltmeter and in series with an ammeter. Switch on the circuit, and measure the resistance, voltage and current. Plot...

I'm watching MIT 8.02 electricity and magnetism () and the lecturer says that there is a derivation of ohm's law but it uses quantum mechanics which is outside the scope of the course. Does anybody know of this derivation and can point me to it? I searched around but can't find anything

Homework Statement What is J in Ohms law in dynamics? Homework Equations Ampères law: \nabla \times H = J_f + \partial_t D = J_f + \partial_t ( \epsilon_0 E + P) \nabla \times H = \nabla \times (\mu_0^{-1} B - M) = \nabla \times (\mu_0^{-1} B) - \nabla \times (M) = \nabla \times (\mu_0^{-1} B)...

Homework Statement In the figure, calculate v_0 and i_0 when v_s = 1 Homework Equations Using Mesh Currents: KVL: The sum of all voltages around a closed loop is equal to zero. Ohm's Law: V = IR Cramer's Rule: i2 = delta2/deltaThe Attempt at a Solution I first designated the lower left loop...

How can Ohm's law explain the fact that the resistance of a wire depends directly on length and inversely with area?

Hi, I just took up a course on biomedical engineering. And i have no background knowledge on engineering, having difficulty in following up in class. Can anyone teach me the basic? i was studying on transducer (sensor/actuator), focusing more on sensor. Ohm's law, KVL, KCL, voltage...

I am confuse at a point that is: I equation P=IV there is an inverse relation between I and V But according to ohm law there is direct relation between I and V. How in in ac Power transmission line 1100 volt cause small current than 220 volt... please solve my this trouble... Everyone...

Suppose I have some resistor with resistance R. Using a typical power supply, application of a voltage difference V across the resistor leads to a current draw of I = V/R according to Ohm's law (so long as the only circuit element is a resistor without any complex impedances). Now, suppose I...

just a quick question about ohms law (v=ir) concerning when there is a parallel and a series in the same circuit. i know the rules like in a parallel, v total is v1+v2... and in a series it is 1/v+1/v2=1/vt. and that's the opposite for Current. but what do i do when there is a series and a...

Homework Statement Homework Equations R = (Rou*A)/L V = R/i The Attempt at a Solution In this one I don't really understand how my answer to part a is wrong. My Work: L = 5.9 cm = 5.9E-2 m diameter = 8.4 mm = 8.4E-3 m ... radius = 4.2E-3 m ... A = pi*r^2 = pi(4.2E-3)^2 =...

Homework Statement Consider two coaxial conducting cylinders with radii a and 3a and length L. The region a<r<2a is filled with a material of conductivity σ1, and the region 2a<r<3a has conductivity σ2. (Assume ε1=ε2=εo.) The inner cylinder is held at potential V0 and the outer cylinder at...

As in, what if you have a VERY high voltage? Then I = V/R. But what if you only have a limited number of charge carriers that could eventually run out? Then what will happen to the current? Will it suddenly stop following Ohm's Law? Will it immediately drop off to 0, or gradually drop off to 0?

Sorry everyone, I forgot to post my efforts in solving the problem, so here I go again: The question says: Suppose you wish to fabricate a uniform wire out of 1.00 g of copper. If the wire is to have a resistance of R=0.500 Ohm, and a density of d=8920 kg/m3, and if all the copper is to be...

This is referring to Chapter 7.1, page 285 of "Introduction of Electrodynamics" 3rd edition by David Griffiths. \vec J = \sigma \vec f \;\; \;\;\;\;\;\;\;( \frac{C}{m^2\cdot sec}) [SIZE="5"](1) Where f is force per unit charge. Is the unit charge one coulomb?. Also \vec J =...

Homework Statement 1. A nine volt battery supplies power to a cordless curling iron with a resistance of 18 ohms. How much current is flowing through the curling iron? 2. A 110 volt wall outlet supplies power to a strobe light with a resistance of 2200 ohms. How much current is flowing...

1. A car, 5 km distance from a station, take 100 A over a 100 mm hard drawn copper trolley wire having a resistance of 0.270 ohm per km. The rail and ground return has a resistance of 0.06 ohm per km. If the station voltage is 750 V, what is the voltage of the car? Homework Equations I...

Hi, Lately I've been concerned about the Ohm's law J=\sigma E and the physical interpretation of this law depending on what is considered the cause and what the effect. More concretely, it is quite natural and intuitive for me the interpretation of this law in one direction: a electric field...

I am an electrician, and I recently got into some trouble on an issue. We were trouble shooting a fan motor that was rated at 240v and was only getting 208v. The more experienced electricians I was with said the amperage was going up because there wasn't enough voltage. This makes no sense to...

Homework Statement R1 = 9.29 V= _____ I = _______ R2 = 9.19 V= _____ I = _______ R3 = 8.45 V= _____ I = _______ R4 = 4.47 V= _____ I = _______ R5 = 9.12 V= _____ I = _______ R6 = 4.60 V=...

[b]1. Given only one 30Ω and one 60Ω, calculate all possible values of resistance that can be obtained. [b]2.I am not certain of which equation I should be using ... I never had other problems which gave only this information, usually the voltage is given or the current. [b]3. Here...

Homework Statement A block of carbon is 3cm long and has a square cross section whose sides are .5cm long. A potential difference of 8.4V maintained across its length. a)What is the resistance of the block? b)What is the current in this resistor? Homework Equations R=pL/A where p is...

I have tried solving, but please check my answers for me. I am not sure if I solved it right.ASAP please. thanks! :) Just the first page please. Thanks!

Homework Statement Two concentric metal spherical shells of radius a and b, respectively, are separated by a weakly conducting material of conductivity sigma. (a) If they are maintained at a potential difference V, what current flows from one to the other? (b) What is the resistance between...

Homework Statement The two headlights of a car require a total of 10 A supplied at 12 V. Given that the combustion of 1 L of gasoline releases 3X 10^7 J and that the conversion to electrical power has an efficiency of 25%, how much gasoline is consumed in one hour for this purpose alone...

help with a circuit and Ohm's law! Homework Statement A) What is voltage V at terminal A with respect to ground? B) Imagine that a wire is connected between terminals A and B. What is the current flowing through the battery? C) With the wire connected between terminals A and B, what...

Homework Statement In the circuit above given that Vg is 55 V, R1 is 3 Ohm, R2 is 12 Ohm and R3 is 90 Ohm. Using the polarity shown in figure answer the following questions. (A) Find the value of i3? (B) What is the value of i2? (C) What is the value of V3? (D) Calculate the power...

A bicycle LED headlight requires 5 V, 250 mA to operate. Using Ohm’s law, determine the equivalent resistance of the light. What is the power consumption rate in W? How many electrons pass through per second? It is powered by four AA rechargeable battery in series. Each battery provides 1.25...

Homework Statement (a) Assuming a resistivity of 1E13 (horseshoe thing)m, calculate the resistance between the ends of a rubber band that is 19 cm long and 2.2 mm in diameter. (b) Calculate the resistance between the 'heads' and 'tails' sides of a penny that is 1 mm thick and 2 cm in...

Homework Statement A 60W lamp is placed in series with a resistor and a 120V source. If the voltage across the lamp is 25V, what is the resitance R of the resistor? Homework Equations I derived R= V2/P from ohm's law to solve this problem. The Attempt at a Solution R= V2/P...

Given: In the circuit shown above, 192 V is dropped across the unknown resistor, Ro. Required: Determine the value of Ro. V = iR, KCL and KVL I really don't know where to go on this one. I know that the right side's voltage will need to add up to zero, but that's about all I know.

Homework Statement Three resistors are connected to a 9.00 V battery: R1 = 100 W, R2 = 200 W, R3 = 300 W. Determine the voltage, current, and power for each resistor for a series connection. Homework Equations V=IR The Attempt at a Solution V_{total}=I_{total}+R_{total}...

Currnet flows from positive to negative right? cause you assume the path a proton would take?! also how much resistance does one ohm provide? does it block 1 volt? and resistors increase voltage and decrease current right? thanks!

OK, Strange question, but I have a very practical, if simple, need to apply the Law. I need to heat a copper wire to several hundred degrees and I am trying to figure out a rough voltage and amperage to push through it. I am staring at...

Homework Statement A cylindrical copper cable carries a current of 1300 A. There is a potential difference of 1.6 10-2 V between two points on the cable that are 0.38 m apart. What is the radius of the cable? I=1300A V=1.6e-2 V l=0.38m rho=1.7e-8(resistivity of copper) r=...

Homework Statement Explain the terms used in the microscopic version of Ohm's Law Homework Equations j=oE The Attempt at a Solution Well I know what we have here is the current density within a conductor is equal to its conductivity multiplied by an 'E-field'. But what is this...

I'm an ASE certified Technician specializing in Brakes and Four-wheel Alignments. I'm going to go for my cert. in Electrical systems this fall. As I began my self-study in electrical systems, I realized...I forgot my Algebra. I'm currently studying Ohm's Law. Within Ohm's Law, I'm studying...

Hey I have a 10amp 12v power supply and a 12v 3amp motor. Is there any way to add enough resistors to use the 10amp power supply with the 3 amp motor? If not is there any thing that I can put in line with the motor and power supply so the 10amps won't burn up my motor? Thanks Stephen Doty

The ohm law for electricity is given by R = V/I Yesterday, my friend just took an experiment report to me which show the relation between R, V and I on a resistor and semiconductor separately. I saw that for resistor, R is almost a constant so V vs I is a straight line. However, for...

Ohmic loss, ohm's law, resistance etc... hello, just a simple question about power dissipation in the form of heat. If a conductor has infinite conductivity (zero resistivity) then the voltage across it is zero, so by the formula P= I^2 R, it dissipates zero power as heat. but if I use...

Homework Statement A solid cube of silver (density = 10.5 g/cm^3) has a mass of 90.0 g. (a) What is the resistance between the opposite faces of the cube? (b) If there is one conduction electron for each silver atom, what is the average drift speed of electrons when a potential difference of...

I'm having trouble understanding the derivation of Ohm's law from the drude model. So you start with a simple sum of forces: \Sigma F_x = - e \: E + F_{collision} = 0 (my understanding is that there are only two forces in Drude's model: those from electron-ion collisions and applied...

An aluminum bar 3.74 m long has a rectangular cross section 1.11 cm by 5.30 cm. What is the resistance ? R = ____ ohms What is the length of a copper wire 1.53 mm in diameter having the same resistance? L= ____ m.

Ohm's Law Yay! :( Homework Statement 1. How does the resistance of most objects vary with voltage? Homework Equations V=RI I=V/RThe Attempt at a Solution They are independent of each other (resistance is a constant).