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

Determine the rate of change of flux - magnetic field, An e.m.f. of 25V is ...

An e.m.f. of 25V is induced in a coil of 300 turns when the flux linking with it alters by 12mWb. Find the time, in milliseconds, in which the flux makes the change. An ignitio

Compute the quantity of sugar contained in the solution, Q A 300 mm long tu...

Q A 300 mm long tube containing 60 cc of sugar solution produces a rotation of 90 when placed in a polarimeter If the specific rotation is 600, Compute the quantity of sugar contai

Obt, Obtain expression for an optical path difference for formation of circ...

Obtain expression for an optical path difference for formation of circular fringe in Michelson''s interferometer

Doppler effect, Doppler Effect Describing the classical Doppler Effect ...

Doppler Effect Describing the classical Doppler Effect for sound waves. The Doppler Effect is a means through that wave properties (specifically frequencies) are influenced thr

Capacitor-start-capacitor-run single-phase motor, Capacitor-start-capacitor...

Capacitor-start-capacitor-run single-phase motor : In this case, two capacitors are used one for preliminary and other for running purpose as shown. The capacitor used for prelimin

Force act on earth, Q. A rubber ball is dropped to the floor. What forc...

Q. A rubber ball is dropped to the floor. What force act on the ball to bounce? Does the Earth "bounce" too? Ans. The force of the Earth pushing back on the ball causes

What force does every one exert on the other, Regard as two charged particl...

Regard as two charged particles. At a given separation every particle exerts a force of 12 N on the other. What force does every one exert on the other after someone moves the part

State coulombs law in electrostatics, Q. State Coulombs law in electrostati...

Q. State Coulombs law in electrostatics? Coulomb's law declares that the force of attraction or repulsion between two point charges is directly proportional to the product of t

Explain how receiver functions in fibre optic communication, Explain how re...

Explain how receiver functions in fibre optic communication system. Receiver: The optical signal received must be first converted within digital form and in case analog outp

Movement of charge, MOVEMENT OF CHARGE: Although electric current is re...

MOVEMENT OF CHARGE: Although electric current is referred to as the flow of electrons through a conductor, it should be noted that more exactly, any movement of electric charge

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