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

Discharging of solar cell, Discharging: The cell is connected across some ...

Discharging: The cell is connected across some load during discharging. As the direction of current by the cell is reversed during discharging the negative ions go in the directio

Determine the angle of the prism, A ray of light travelling in air is incid...

A ray of light travelling in air is incident on a prism and passes through it with a speed of 2X10 8 ms -1 parallel to its base. If the angle of refraction is similar to half of

Chemical action in lead acid battery, Chemical action in lead acid battery:...

Chemical action in lead acid battery: When the lead acid battery is delivering current, the sulphuric acid breaks up into Hydrogen ions (H 2 ) carrying a positive charge and Su

Explain logarithmic decrement, Explain logarithmic decrement? Evaluate the ...

Explain logarithmic decrement? Evaluate the ratio of nth amplitude with 1st amplitude in case of under damped oscillation.

Astronomy, The birghtness of objects past Neptune actually varies approxima...

The birghtness of objects past Neptune actually varies approximately as 1/d^4. Why is that the case?

What is the circumference of the ball, Suppose a baseball rolls 3.2 m acros...

Suppose a baseball rolls 3.2 m across the floor. If the ball's angular displacement is 82 rad, what is the circumference of the ball?

How far will it travel in that time interval, If the velocity of the box in...

If the velocity of the box in problem 10 was 5.0 m/s at time zero, what will be its speed after 0.50 s? How far will it travel in that time interval?

Evaluate the minimum value of h in terms of r, A sled slides down a frictio...

A sled slides down a frictionless track and loops the loop without falling off. What is the minimum value of h  in terms of  r ? The only other information given is that the an

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