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

Explain the phenomena due to surface tension, (i)  Lead balls are spherical...

(i)  Lead balls are spherical in shape. (ii) Rain leaves and a globule of mercury placed on glass plate are spherical. (iii) Hair of shaving painting brush, when goes in wate

River boat vectors and projectiles, River Boat Vectors and Projectiles ...

River Boat Vectors and Projectiles Suppose the motion of the river boats below. Within that case, the boat is heading across the river. Inside the top case, the presence of a c

Determine displacement current, Show that the displacement current flowing ...

Show that the displacement current flowing between the two plaes of the capacitor is similar to the conduction current utilized in charging the capacitor.

Power series, Invoke the boundary condition Φ '(0)=0 to obtain a power seri...

Invoke the boundary condition Φ '(0)=0 to obtain a power series where the powers of x are multiples of 3.

P2 work, what is the tension in the string when the block is lifted at a st...

what is the tension in the string when the block is lifted at a steady speed when the weight weighs 4.5N and the distance is 90cm

Explain radioactivity and its problems and applications, Explain Radioactiv...

Explain Radioactivity and its Problems and Applications ? All radiation, electromagnetic as well as the kind from nuclear decay, takes its toll on living organisms. If the radiati

Electrostatic, Why we are showing work done over a closed path is zero to ...

Why we are showing work done over a closed path is zero to prove that electrostatic forces are conservative

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