Inductors, Physics

Assignment Help:

Inductors:

Coils which are used for their opposition to current change in a circuit are known as inductors or chokes.

CONSTRUCTION

Inductors with an air core have small inductance values and are used at high frequencies within radio tuning circuits, or as r.f. chokes to stop radio frequency currents taking certain paths in circuits. Coils for use at high frequency are made of Litz wire which consists of several thin copper wires insulated from each other.

Materials based on iron are used where a large inductance is required. Iron increases the strength of the magnetic field several hundred times. Silicon steel and nickel iron are used at frequencies up to 20kHz.

Iron cores are laminated. The laminations reduce the conversion of electrical energy to heat by making it difficult for currents in the coil to induce currents in the core. These induced currents are called ‘eddy currents' because they flow in circles through the iron core. If the laminations are at right angles to the plane of the coil windings, the core offers a large resistance to the eddy currents.

Iron based cores can be used at high frequencies if the material is in the form of a powder which has been coated with an insulator and pressed together.

Ferrite cores consist of ferric oxide combined with other oxides such as nickel oxide and may also be used at high frequencies.

Iron dust and ferrite cores increase the inductance of a coil considerably. For example, an air cored inductor of 1mH could be increased to 400mH by fitting a ferrite core. These cores also have a high resistance, thereby reducing eddy currents.


Related Discussions:- Inductors

Derive equation for an electromagnetic wave, Derive mathematical equation f...

Derive mathematical equation for an electromagnetic wave travelling in a charge free conducting medium in terms of electric field vector.

Resistivity, RESISTIVITY: R esistance may be defined as that property ...

RESISTIVITY: R esistance may be defined as that property of a substance which opposes (or restricts) the flow of current (or electrons) through it. The practical as well as MK

Experiment of measuring jar or graduate, A measuring jar or graduate Se...

A measuring jar or graduate Select several straight-sided glasses jars of assorted sizes. Olive bottles are very useful for the making of graduated cylinders. Paste a strip of

Measurement of difference in wavelength, Measurement of Difference in Wavel...

Measurement of Difference in Wavelength of Sodium D1 and D2 Lines: For the measurement of difference in wavelength of two closely spaced sodium lines firstly the M1 is adjusted for

Phenomenon of photoelectric effect?, A radiation of 500nm is incident on a ...

A radiation of 500nm is incident on a metal surface whose work function is 3ev.why do we not observe the phenomenon of photoelectric effect? Ans) Because the energy of radiation i

Current during the resistor, Ques: A 12 volt battery is associated in...

Ques: A 12 volt battery is associated in series with an initially-uncharged 120 microfarad capacitor and a 25 ohm resistor. What is the current during the resistor at the ins

Distinguish between the terms average value and rms value, A convex lens of...

A convex lens of refractive index 1.5 has a focal length of 18 cm in air. Measure the change in its focal length when it is immersed in water of refractive index. Distinguish am

Illustrate bio-savart law, Illustrate Bio-Savart law. Describe instantaneou...

Illustrate Bio-Savart law. Describe instantaneous, rms, and maximum values of a current.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd