How is induced current in a secondary coil is related to current in primary coil?
Answer. When the current changes in the primary coil then the magnetic field is induced in the primary coil and which get associated with the secondary coil through a metallic core. Due to the change in magnetic field across secondary coil, a current is induced in the secondary coil.
Why the primary and secondary coils of a transformer are preferably wound on the same core?
Answer. The primary and secondary coils of a transformer are preferably wound on the same core so as to obtain tight coupling between the primary and secondary on each winding.
Which type of transformer core is most efficient?
Toroidal cores are more efficient at handling the same kind of energy load than steel laminated E shape cores, and can be made smaller, lighter, and with a lower magnetic field. However, windings tend to be more expensive for toroidal cores.
How laminating the core of a transformer helps to reduce eddy current losses in it?
b) Lamination is done to reduce the eddy current loss by increasing the resistance of the core. Thus, the laminated sheet will have an eddy current that circulates within it but the sum of individual eddy currents of all such laminations are very less compared to that of using single solid iron core.
Why does lamination reduce eddy current?
As the laminations are thin, they will have relatively high resistance. The planes of these sheets are placed perpendicular to the direction of the current that would be set up by the induced emf. The planes of these sheets are arranged parallel to the magnetic fields so that they can cut across the eddy current paths.
Why eddy current is produced?
They can be created when a conductor is moving through a magnetic field, or when the magnetic field surrounding a stationary conductor is varying i.e. anything which results in the conductor experiencing a change in the intensity or direction of a magnetic field can produce eddy currents.
How can hysteresis and eddy current loss be reduced?
The eddy current loss occurs because of the interaction of magnetic field and conductor. The hysteresis loss occurs because of the reversal of the magnetism. The eddy current loss is minimised by using the thin core of lamination. The silicon steel material is used for minimising the hysteresis loss.
What is the formula for hysteresis loss?
Therefore, Energy consumed per cycle = volume of the right x area of hysteresis loop. The hysteresis loss per second is given by the equation[20]: Hysteresis loss, Ph= (Bmax)1.6f V joules per second (or) watts.
What is meant by hysteresis loss?
Definition: The work done by the magnetising force against the internal friction of the molecules of the magnet, produces heat. This work, done by the magnetising force produces heat; thereby causing wastage of energy in the form of heat is termed as hysteresis loss. …
What is the advantage of eddy current?
The advantages of eddy current testing are: Sensitivity to surface defects. Able to detect defects of 0.5mm in length under favourable conditions. Can detect through several layers.
What is the disadvantages of eddy current?
Disadvantages of Eddy Currents: There is a major heat loss during cycling eddy currents due to friction in the magnetic circuit, especially where the core is saturated. Thus there is the loss of useful electrical energy in the form of heat. There is magnetic flux leakage.
What are merits and demerits of eddy current?
Eddy current converts the kinetic energy into heat and this is applied in many useful applications like Magnetic Braking in trains, Electromagnetic damping, Induction furnace etc.In this process, there is a loss occur in this system to reduce this we need to increase the core resistance and there is more losses in eddy …
Are eddy currents good?
The changes in the magnetic field are so rapid that very large eddy currents are generated and heat produced is sufficient to melt quickly. Eddy currents can also be harmful. It is well known that the rapidly changing magnetic fields can generate dangerous eddy currents in the human body.