Inductance Definition and 495 Threads

Homework Statement Homework EquationsThe Attempt at a Solution Here are two questions. I'm stuck on question 1, and need someone to check question 2. For the first question I see C2, C3, and C4 in parallel, so Ceq of those 3 are C2 + C3 + C4 = 3C but now how do I continue? seems like the 3...

So from Faraday's law, a change in the magnetic flux will induce an emf on a loop of wire. { \phi }_{ B }\quad =\quad BA\\ { \varepsilon }_{ ind }\quad =\quad \frac { d{ \phi }_{ B } }{ dt } (in this case a perpendicular field) From these equations, it looks like the only way to induce a...

Homework Statement In the following figure, R1= 3.1 Ω, R2= 4.9 Ω, L1= 0.155 H, L2= 0.2 H and the ideal battery has ε = 5.6 V. Just after switch S is closed, at what rate is the current in inductor 1 changing? Homework Equations { \varepsilon }_{ induced }\quad =\quad L\frac { di }{ dt } \\...

I originally posted this to the advanced homework -section, but maybe this isn't advanced enough to warrant being posted there :oops:. If a mod sees this, feel free to delete the original on the other forum. I'd do it myself, but I can't. 1. Homework Statement Calculate the mutual inductance for...

Homework Statement A long, straight wire has a line charge, λ, that varies in time according to: λ = λ0 exp(-βt). A square wire loop of dimension a is located adjacent to the wire at a distance of a from the wire. Calculate expressions for the displacement current at the center of the wire loop...

Homework Statement Hi, I have some data taken on voltage and resistance of a coil part of a yttrium barium copper oxicde (ycbo) superconductor. I have no information about the coil itself. A thermocouple attached to the superconductor also measured the temperature of it as it was cooled. This...

Homework Statement In the following figure(Figure 1) switch S1 is closed while switch S2 is kept open. The inductance is L = 0.360 H, the resistance is R = 31.0 Ω , and the emf of the battery is 22.0 V . At time t after S1 is closed, the current in the circuit is increasing at a rate of di/dt =...

Good evening everyone. I have a misconception regarding self inductance. I know that back emf induced in an inductor starts with the same value of the original voltage source and then keeps decreasing to reach zero. I also know how this is related to the derivative of current with respect to...

Homework Statement a solenoid inductor consists of 200 closely spaced turns, length = diameter = 5cm. calculate inductance. Homework EquationsThe Attempt at a Solution H = NI/L L = N (flux) / I - you can't use this because the length is equal to the diameter. What equation do I use?

I'm sure you are all familiar with calculating the inductance of a long transmission line. We first calculate the partial self inductance and we add to the partial mutual inductance due to the current in the other conductors. Looking at the image of a single-phase system, where I1 + I2 = 0...

Hey guys, I am trying to design an Inductive Square Antenna Coil that will be milled onto my PCB. I am slightly confused when it comes to the matching circuit. To my understanding the matching circuit is there to have the same impedance value of the antenna, correct? So my matching circuit...

Homework Statement Homework Equations Adding inductors in series and parallel (same as resistors) The Attempt at a Solution This is the first time I ran into a circuit like this with diagonal wiring and I am not sure how to treat it. Do I add the inductors in the triangle in series? So...

I've attached a picture of my book. So there is a figure of two inductors mutually connected. The book says that initially, current 1 and current 2 are zero. Then when current 1 goes from 0 to I1, the energy stored in circuit is only the energy in inductor 1. <-- This is my question, but...

Homework Statement Find effective value of voltage between points 3 and 4. The diagram on the right shows behaviour of current i. Homework Equations [/B] $$ u_M= M \frac{di}{dt} $$ The Attempt at a Solution [/B] I tried with formula above, didn't work for me. I haven't seen how to solve...

The thread name is probably misleading, but I just want to make sure I'm clear in that: Are the only two problems caused by leakage inductance (stray magnetic flux causing imperfect mutual coupling) in a transformer, that of; - poorer voltage regulation & - EMI noise on other equipment (?)...

A constant voltage V is applied at the two ends of a cable which is a perfect conductor (e.g. a superconductor). Since the cable, anyway, has a non zero inductance L, the current inside it is not infinite but it is proportional to time t: i(t) = V/L * t. In this situation, how much it is the...

If current I passes through a circular loop of radius R,then what will be the self inductance of that loop? (calculating flux through the loop leads to calculating magnetic field at every point inside the loop which is an elliptic integral.)

I have read this chapter about calculating internal and external inductance of a straight wire here. http://nptel.ac.in/courses/Webcourse-contents/IIT-KANPUR/power-system/chapter_1/1_4.html Seeing the flux linked with the conductor itself, emf due to that flux induced in upper half and lower...

Speaking just of long straight wires, not loops, coils or solenoids. Ideal wires have no resistance. Of course they would have no capacitance. And real wires have some very small amount of inductance, no? Firstly, would an ideal wire have some ideal nonzero inductance? Why/why not? After all...

Im trying to compare, visually in my head, the difference between transmitting data vs something like radio or microwaves vs how inductance and capacitance. I understand that the way the wave is modulated for example, AM or FM, can be interpreted as 0s or 1s. Im trying to compare this to...

Homework Statement Find Io(s)/Ii(s) Homework Equations Basic KVL laws. The Attempt at a Solution My idea is to start from the RHS of the circuit until I get a relation between Io(s) and Ii(s). Actually I stopped at this point, I wondered whether my approach is appropriate or not since...

Homework Statement A finite solenoid with "N" turns of wire, "L" length , "R" is the radius of the solenoid and passes through it a current "I". The objective is to calculate "L" of a finite solenoid. Not the basic formula ##L=\frac{\mu_0·N^2·S}{Length}## which is for a infinite solenoid. See...

Hi, I'm trying to calculate the length of wire that I need to wound a coil using a spool and wire of known dimensions. I was trying to use this converter but I'm not getting good results: http://www.had2know.com/technology/solenoid-coil-wire-calculator.html For instance: with a wire radius of...

Homework Statement An inductor is connected to the terminals of a battery that has an emf of 12.0Vand negligible internal resistance. The current is 4.86mA at 0.940ms after the connection is completed. After a long time the current is 6.45mA. Homework Equations V = IR V(t) = V0 (exp(-t/τ))...

Homework Statement An electric fan which is plugged into a 115 V(rms), 60 Hz socket in your house can be considered as made up of a 1500 Ω resistor in series with a 1.4 H inductance. How much power is dissipated by this electric fan on the average? (in W) Homework Equations P = IV = I^2 R I =...

Homework Statement We have coil connected to dc supply and a secondary coil connected to load. We cross the secondary coil with the primary and emf of mutual inductance is induced at that verry moment. Then the induction stops for there is no more change in the flux. However, if an emf is...

Homework Statement Two identical long wires of radius a = 2.90 mm are parallel and carry identical currents of i = 5.00 A in opposite directions. Their center-to-center separation is W = 17.0 cm. Neglect the flux within the wires but consider the flux in the region between the wires. What is...

I found this formula to approximate the inductance of a coil of wire. But what if a solenoid were composed of N separate loops, where each loop of the solenoid is connected to its own battery? That is, what if the solenoid had the same number of loops and the same geometry, except that each loop...

This thread is continuation to: https://www.physicsforums.com/threads/self-inductance-of-a-straight-current-carrying-wire.461622/ It's a really old thread, but I happened to come across the same problem a while back and since the old thread does not give the correct answer, I decided to create...

Suppose that a ferrite bead is put around a cable where a constant current I flows, just like in this image. The coordinate system has the z axis along the cable. Let's evaluate the current through the (x,y) plane: according to the Ampère's law, the only magnetic field component generated by...

Although I'm sure the answer is obvious, but why are solenoids used as inductors? Why don't entire circuits in general have inductor properties, since the entire circuit creates magnetic fields? More specifically, why don't random points along a circuit do the same thing as a solenoid (retain a...

The question is the following: a) Determine all load voltages and currents b) Determine the resistance reflected into the primary. Answer a) R(l): 35V, 2.91A, X(cl): 15V, 1.5 A The answer to part (b) is apparently 34.5 Ohms. How did they arrive at these answers? I am not sure...

Homework Statement Hello, I am going to ask a rather simple question yet I wasn't able to solve. I have a circuit which I wanted to find out about the equivalent resistance and inductance. I know how to find the equivalent resistance of two resistors in parallel as well as two inductors in...

Hello. Maybe this is the one of the most typical example in Electromagnetism textbook. There is a single round wire carrying current I (in D.C) with radius of R and length is infinity. From Ampere's law, the B field inside the wire is B = μIρ/2πR2 aθ where ρ is radial distance from...

I am studying about transformer and get confused about some concept. I have learn that in an ideal simple transformer the primary has two components of current: Magnetization current i.e. the open-secondary primary current. Current that (ignoring small leakage inductances) finds it way (via...

Homework Statement A rectangular coil is composed of 150 turns of a filamentary conductor. Find the mutual inductance in free space between this coil and an infinite straight filament on the z axis if the four corners of the coil are located at Homework Equations B = (phi-hat) μoI/2πr dS =...

Given a flexible wire loop of a certain perimeter and planar shape, what are some good ideas to minimise the loop's inductance? For example, would it work if i surrounded the wire loop with a superconducting loop in the same plane?

I'm using a U-Shaped Ferrite Core with coils in both legs of the U. I've calculated it's inductance using an analogy between electric/magnetic circuits. L = N2/Rtotal where: N = number of turns of coil in both legs of the U; Rtotal is the total reluctance of my circuit = R1 + R2 R1 =...

In an inductor, a current waveform 90o out of phase with the voltage waveform creates a condition where power is alternately absorbed and returned to the circuit by the inductor. If the inductor is perfect (no wire resistance, no magnetic core losses, etc.), it will dissipate zero power. I...

I am planning to build a rogowski coil but not the conventional one, which is a circular loop. Below is the example of a rogowski coil so you have the big picture of my question. In the picture, the current conducting wire (with current Ip) is encircled by a big circular loop rogowski coil...

Hello! First of all excuse my English. I'm Swedish. I'm doing an exprement in which I utilize the energy from the rotation in a stroller wheel to charge a 5V battery . I plan to make a magnetic generator with a disc placed on a 10 " wheel, consisting of the 20 Neodymium magmeter on the radius...

rude man submitted a new PF Insights post Misconceiving Mutual Inductance Coefficients Continue reading the Original PF Insights Post.

Homework Statement "Consider a square metal picture frame of side length s, mass M, and total electrical resistance R. It is dropped from rest from a height H above a region of uniform magnetic field pointing into the page. The frame accelerates downward under the influence of gravity until...

Homework Statement Homework Equations[/B] ∫BdL = μi Φ = BA (flux) S= NΦ/i (self inductance) M = NΦ/i (mutual inductance) The Attempt at a Solution a) ∫BdL = μi BL = μi B = μi/L since the solenoid has N1 turns B = μiN1/L b) flux Φ = BA = AμiN1/L self...

My observation is to verify self inductance formula by measuring the resonant frequencies of different coils in an LC circuit.For this, I am asked to use this formula by my mentor : L = 1/(4π^2 . f^2 . C) Here, f = different resonant frequencies, C = capacitance of the capacitor in the LC...

Homework Statement For both the LR and RLC circuit, a function generator is used to create a 1000 Hz square wwave of maximum amplitude. 1) For the following LR circuit, the resistance is set to a 100 Ohms. Determine the inductance, L. How does the inductance vary if the resistance were...

1. A resonant RLC circuit can be used as an amplifier for a certain band of frequencies around the resonant frequency. Consider a series RLC circuit as an audio band amplifier with an AC voltage source as the input, and the voltage across the 8.0Ω resistor as the output. The amplifier should...

1. Two wires running parallel to each other in a circuit can provide an inductance that is adjustable with their length. For the loop shown below with length L=2m , width w=5cm , and wire radius a=1mm , find the inductance in H?Homework Equations3. I thought i could find the inductance by...

Homework Statement I have to answer a few questions about a lab session I did (university) and I'm really stuck with this one. The objective of the lab session was to find the self inductance (L) of a solenoid. In order to do that, I had a function generator exciting a solenoid with a high...

Hi, I know that the permiability (mu) changes as the core material saturates and I would have thought L1 = N12 / reluctance L2 = N22 / reluctance and they'd both share the same reluctance length, this would indicate to me that L1 and L2 are only a function of mu. Is this correct? I know also...