What is Inductance: Definition and 494 Discussions
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the current, and follows any changes in current. From Faraday's law of induction, any change in magnetic field through a circuit induces an electromotive force (EMF) (voltage) in the conductors, a process known as electromagnetic induction. This induced voltage created by the changing current has the effect of opposing the change in current. This is stated by Lenz's law, and the voltage is called back EMF.
Inductance is defined as the ratio of the induced voltage to the rate of change of current causing it. It is a proportionality factor that depends on the geometry of circuit conductors and the magnetic permeability of nearby materials. An electronic component designed to add inductance to a circuit is called an inductor. It typically consists of a coil or helix of wire.
The term inductance was coined by Oliver Heaviside in 1886. It is customary to use the symbol
L
{\displaystyle L}
for inductance, in honour of the physicist Heinrich Lenz. In the SI system, the unit of inductance is the henry (H), which is the amount of inductance that causes a voltage of one volt, when the current is changing at a rate of one ampere per second. It is named for Joseph Henry, who discovered inductance independently of Faraday.
Find the mutual inductance (H) of the solenoid and coil shown below. The solenoid has 5263 turns per meter and an area 112 cm^2, and the coil has 230 turns and an area 19 cm^2.
I know that mutual inductance = (N1 Φ1)/ I2 but I have no idea where to begin since they don't provide the...
Homework Statement
Homework Equations
Φ = M*I
Biot-Savart law
Ampere's law
The Attempt at a Solution
I have the formula Φ = M*I, which means that to find the mutual inductance I simply need to find the magnetic flux through the top circuit due to the current in the bottom...
I have a few statements that I have to discern whether they are true or false and I am down to my last guess and am completely stumped.
1. No EMF will be generated by a coil rotating inside a magnetic field if the axis of rotation is perpendicular to the field.
2. In an electrical...
I'm having a bit of trouble getting the right answer for a problem in my electrical engineering textbook. The question is:
At t=0, the current flowing in a 0.6H inductance is 8A. What constant voltage must be applied to reduce the current to 0A at t=0.4s.
I'm using the equation...
Homework Statement
I have a part of circuit with 2 inductors (L1, L2) of given values having a given mutual inductance, and a (capacitor+inductor L3) parallel to L2. Please find attached the circuit.Homework Equations
Find the impedance of this part of the circuit.The Attempt at a Solution
(all...
help me please! [Inductance]
Homework Statement
an experiment to determine the inductance and internal resitance of an inductor in a series LCR circuit.
I am proved with an a.c. power supply, an inductor, a capacitor substitution box, a resistor and an a.c. voltmeter
Homework Equations...
I have to make a solenoid to operate some device. Can anybody let me know what formula to use to calculate number of turns for a solenoid wound on some metal. I also want to calculate the force.
Does this formula works
B = uourNI/L
&
F = ILB
I am studying the relationship between transmission speed in a Transmission Cable and the temperature of the cable. This speed is given by (as per discussion in the Feynman lectures)
v=\frac{1}{\sqrt{LC}} where
L is the inductance per unit length
C is the capacitance per unit length...
Homework Statement
How will a coil's self inductance change if you unwind it and then re-wind half of the length of wire into a coil with the same diameter but with half of the number of turns?
The answer is that it will decrease by 1/4, but I don't understand why it isn't 1/2 instead...
Inductance & magnetic flux problem -- please help
Homework Statement
The magnetic field of a place on Earth has strength 55 microTesla and is tilted 60 degrees below horizontal. A 200 turn coil with diameter 4cm and resistance 2 ohms is connected to a 1 microFarad capacitor. The coil is...
Homework Statement
Give a definition of (self) inductance. Suppose a battery, which supplies a constant EMF ϵ_0 is connected to a circuit of resistance R and inductance L at t = 0. Find an expression for the current as a function of time.
Homework Equations
V = IR
V =...
a. The reactance of an inductor is 100 ohms at 2kHz. What is the inductance of this inductor??
b. At what frequency is the reactance of a 3.5-mH inductor equal to 10 ohm?
I am not even sure what equations to use for these two questions. I know that for a the inductive reactance equation...
hello Forum,
why is the voltage on a capacitor not instantaneously following the change in the current (which follows the change in the generator source voltage)?
Where does the delay come from (90 degree phase retardation)?
WE can think of the capacitor as having some inertia.
The same...
Homework Statement
An AC generator produces a voltage of 230<45º volts. It is connected across an impedance of 17.4<-33º ohms.
The supply frequency = 50Hz
I got my assignment back and this question wrong, maybe you can guide me, please because I’m not sure entirety. Help is...
Homework Statement
An AC generator produces a voltage of 230<45º volts. It is connected across an impedance of 17.4<-33º ohms.
The supply frequency = 50Hz
I got my assignment back and this question wrong, maybe you can guide me, please because I’m not sure entirety. Help is...
I'm trying to setup a DC filter to remove noise that's is entering an amplifier circuit. It's just standard line current noise at 60Hz. I can't figure out how on the other hand how to calculate the necessary values to pick an inductor that will do the job.
The DC power in is 16V @ 4A, DC...
I'm having some trouble calculating the values I need for a capacitor and inductor for a passive filter. The values that I know to use are current, voltage and frequency. But I have a voltage <1 volt and a frequency of 60Hz but no current. Can someone help me figure out what value of capacitor...
inductance, flux, capacitance
1. Homework Statement
The magnetic field at one place on the earth’s surface is 55 μT in strength and tilted 60°
down from horizontal. A 200-turn coil having a diameter of 4.0 cm and a resistance of 2.0 Ω
is connected to a 1.0 μF capacitor rather than to a...
Homework Statement
The magnetic field at one place on the earth’s surface is 55 μT in strength and tilted 60°
down from horizontal. A 200-turn coil having a diameter of 4.0 cm and a resistance of 2.0 Ω
is connected to a 1.0 μF capacitor rather than to a current meter. The coil is held in a...
Homework Statement
A series RLC circuit has a resonant frequency of 6.00 kHz and a resistance of 575 ohms. When connected to an AC power supply that varies the voltage at 8.00 kHz, its impedence is 1.00 kOhms. What are the capacitance and inductance of the circuit?
Homework Equations...
wts the practical importance of inductance in dc and ac working?
application of ideal current and voltage sources(dint know dey had specific applications till the time i saw dis question in a college paper...i thought dey were just theoretical...)?
how does an ammeter measure the rms value...
Homework Statement
A square loop made of wire with negligible resistance is placed on a horizontal frictionless table. The mass of the loop is m and the length of each side is b. a nonuniform vertical magnetic field B=B0(1+kx) exists in the region, where B0 and k are constants. The loo is...
Homework Statement
A square loop made of wire with negligible resistance is placed on a horizontal frictionless table. The mass of the loop is m and the length of each side is b. a nonuniform vertical magnetic field B=B0(1+kx) exists in the region, where B0 and k are constants. The loo is...
Homework Statement
Find the mutual inductance between an infinitely long wire and a single loop of wire separated by a distance d. (radius = a)
Homework Equations
The Attempt at a Solution
I've adjusted the magnetic flux density to a coordinate system to make everything easier
B =\frac{...
Homework Statement
21. A certain transmission line is constructed from two thin metal “ribbons”, of width w, a very small distance w<<h apart. The current travels down one strip and back the other strip. In each case it spreads out uniformly over the surface of the ribbon.
a) Find the...
I have noticed there are different Inductance formula's for a various types of air coils & there design, single layer spiral, flat wound spiral, multilayer etc.
My question is for the design of Jumble wound --- Random wound air core coils:
What is the Inductance formula for a Jumble...
A circuit contains two inductors of 6.0 mH inductance in series placed in parallel with an inductor of 8.0 mH inductance. After one of the 6.0 mH inductors burns out, the repair person wants to replace all three inductors with one inductor of equivalent inductance. What inductance should she...
Urgent HW help!
In this problem you will calculate the inductance of an inductor from a current measurement taken at a particular time. Consider the L-R circuit shown in the figure. Initially, the switch connects a resistor of resistance R and an inductor to a battery, and a current I_0 flows...
[SOLVED] Inductance RL Circuit
Calculate the inductance in an RL circuit in which R = 0.300 and the current increases to one fourth its final value in 1.40 s.
I tried doing this with V=IR, (I know, the easy way didn't work).
I also tried I= V/R(1-e^(Rt/L)) but I don't know what V would...
Hello,
I need to measure ONLY a change in inductance of a loop (long wire) which has got resistance about 30-200 ohms.
I have tried to build the oscillator according to this schematic : http://ironbark.bendigo.latrobe.edu.au/~rice/lc/
but the problem is it works well with an inductance with...
Is there a theoretical limit to the time constant of an electric motor?
I was think, if inductance is simply the conversion of current into the magnetic field, and if increase in resistance limits that current for a given power supply, that having a higher time constant would in effect allow...
Homework Statement
A long, solonoidal coil with 2000 turns produces a B field pf 3mT at its center when a current of 1A flows through the coil. If the cross sectional area of the coil is: 2*10^-3 m^-2, and the field is uniform throghout the solonoid, determine the self inductance of the oil...
Does anyone know how to code the following?
I have six inductors in series and would like to couple them to one another.
i.e.
L1 1 2 1u
L2 2 3 1u
L3 3 4 1u
L4 4 5 1u
L5 5 6 1u
L6 6 7 1u
Ideally I'd like to do:
K12 L1 L2 0.3
K23 L2 L3 0.4
K34 L3 L4 0.2
K45 L4 L5 0.5
K56 L5 L6 0.4...
An RLC circuit consists of a 48 ohm resistor, a 200 uF capacitor, and an inductor. The current is 2.5 A rms when the circuit is connected to a 120 V/60 Hz outlet.
a. What is the inductance?
b. What would be the current if this circuit were used in France, where the outlets are 220 V/50 Hz...
A coil has a resistance of 2.10 ohms. The potential difference across the coil is 11.6 V at an instant when the current through the coil is 5.00 A and is decreasing at a rate of 36.0 A/s. What is the coils inductance?
I thought i could use the equation
X=2pi fL to solve for L.. but i am...
Homework Statement
A solenoid is wound with a single layer of copper wire of radius 0.38 cm. The solenoid is 4.5 cm in diameter and 3 m long. What is the inductance of the solenoid per unit length? Assume that adjacent wires touch each other and that insulation thickness is negligible.
radius...
1. Inductor & Resistor connected in series
A circuit comprising of an Inductor & Resistor connected in series.
The values are:
R1 resistor Value 680Ω
Resistance of the Inductor's Windings: (R of L) 98.2Ω
Supply Voltage: 13.2V
Circuit Current: 8.1mA
Supply Freq: 50Hz
Voltage across the...
I read that the unit of inductance is the measure of the time it takes for a current to fully establish itself through the inductor.
Is the reason it takes longer in some inductors for the current to establish itself because it creates a greater magnetic flux? Can the henry also tell you the...
Homework Statement
For coupled coils in this arrangement (illustration attached), show
L_{eq} = \frac{L_1 L_2 - M^2}{L_1 + L_2 - 2M}
Homework Equations
KVL (mesh analysis)
The Attempt at a Solution
As you can see, I get to a final answer - which is not exactly the same...
Homework Statement
A square, single-turn wire coil L = 1.13 cm on a side is placed inside a solenoid that has a circular cross section of radius r = 2.77 cm, as shown in the figure below.
Basically a big circle with a square in the center.
The solenoid is 20.0 cm long...
Homework Statement
A sinusoidal input is applied to the circuit below. Sketch the waveforms of each of Vr (voltage of resistor), Vc (capacitor) and Vl (inductor) on the one graph with particular attension to the phases (the amplitudes are not important) Hint: Vc is proportional to the...
Homework Statement
Find the mutual inductance in air between a long straight filament and a coplanar square loop, 10cm on a side, with its nearest edge parallel to and 10cm from the filament.
Homework Equations
What equations should be best in solving this problem?
The Attempt at a Solution...
On wikipedia they give a fairly simply explanation of inductance
But on http://www.electronics-tutorials.com/ they give a different definition
I don't understand the latter there. Theyre saying any solenoid resists current and the higher the inductance the higher the resistance...
I am a student of the electrical engineering in the university of Munich. I tried to solve a homework but I have some difficulties.
I have tried to use different methods. unfortunately, unsuccessfully.
I will be very glad if you could help me. in fact I wanted to calculate the mutual...
If I place a pipe filled with WATER inside of a coil and then half filled pipe of same material, does the inducatnec change? Will the change be able to be observed using multimeter? any ideas?
Homework Statement
a non inductive resistor passes a current of 20A rms, when connected to a 100v rms supply (50HZ). When connect in series with a pure inductor across a 230v supply the combination draws a current of 15A calculate impedance of the circuit, inductance of the inductor...
inductance of a capacitor-urgent
Hi,
Please can someone help me quickly with this problem:
Use both the flux and energy methods to calculate the inductance per unit length of a pair of parallel, planar conductors of length l , width w, and spacing d . Assume l >> w>> d and neglect...