ELECTRICAL EASY

In this post we will discuss, why electric field inside a conductor is zero. This is very basic but important concept to understand. So we will start will zero and will move further to explain this. Let us assume that a conductor is kept in an external uniform electric field E . The direction of electric field E is shown in the figure. Before starting the discussion, there are two points to know. 1)       Negative charge move in the direction opposite to the direction of electric field. 2)       Positive charge move in the direction of electric field. As we know that, a conductor has a lot of mobile or free electrons, therefore when keep the conductor in an external electric field, electrons will experience a force in the direction opposite to the direction of electric field E and will start accumulating at surface A of the conductor. As electrons are moving opposite to the direction of Electric Field E , pos...

Coulomb's law is an experimental law formulated in 1785 by the French colonel, Charles Augustin de Coulomb. It deals with the force a point charge exerts on another point charge. By a point charge we mean a charge that is located on a body whose dimensions are much smaller than other relevant dimensions. For example, a collection of electric charges on a pinhead may be regarded as a point charge. Charges are generally measured in coulombs (C). One coulomb is approximately equivalent to 6 X 10 18 electrons; it is a very large unit of charge because one electron charge e = -1.60 X 10 -19 C. Coulomb's law states that the force between two point charges Q 1 and Q 2 is: a) Along the line joining them b) Directly proportional to the product Q 1 Q 2 of the charges c) Inversely proportional to the square of the distance R between them. Mathematically we can write as below. F = kQ 1 Q 2 / R 2   ……………………(1) where k is the proportionality constant. In SI units, charges Q 1 and Q 2 a...

Magnetic Circuit is defined as the path followed by a Magnetic Flux. Magnetic Flux always has a tendency to follow low Reluctance path. The laws of Magnetic Circuit are quite similar to the Electric Circuit but the terms used in Magnetic Circuit analysis is different. Let us consider a Toroid having a magnetic path of length L meter. Mind that length of Magnetic path is equal to the periphery of the Toroid. Also, assume that the Cross Sectional area of the Toroid is A m 2 and N number of turn is wound on the Toroid carrying current I as shown in figure below. As we know that, Magnetic Field Strength H inside Toroid = NI / L Wb/m 2 So, Magnetic Flux Density B = u 0 u r H Where u 0 = Absolute permeability of free space             u r = Relative permeability Therefore, total Flux produced in Toroid, Ø = B x A                     ...

Motional EMF is the potential difference produced across the length of a conductor moving in a Magnetic Field. Suppose a conductor of length l is moving with a velocity v in a uniform magnetic field B as shown in figure below. As the conductor is having mobile electrons which can move freely, therefore we can say that electrons of conductor is also moving with a speed of v in an external magnetic field B. Therefore, force experienced by the electrons F = e ( v x B ), here bold letter means vector form. Form the basic knowledge of cross product of two vectors; we can conclude that the direction of force on the electrons of conductor will be upward.  Because of this upward force on electrons, electrons of conductor will start accumulating at the upper portion A of conductor. Since the movement of electron in in upward direction, therefore we can say that positive charge of the conductor is moving downward. Mind that positive charges do not move actually...