Current Electricity Class 12 Notes
Current electricity is the most important chapter for the board exam of class 12, so about all students make self-written notes of this chapter or also want to be download notes on the internet. so I create notes for those students who don’t make a note by yourself. let’s start to discuss some parts of current electricity class 12 notes.
In Chapter 1 Electric charge and fields, all charges, whether free or bound, were considered to be in rest. Moving charges create an electric current. A similar current is found in many situations in nature. Lightning is a phenomenon in which charges reach clouds from the Earth through the atmosphere, sometimes resulting in terrible consequences. The flow of charge in lightning is not constant. But in our daily life, we see charges flowing in many ways in the same way that water flows in rivers. Torch and cell-powered clock are some examples of such devices. In this study, we will study some basic rules related to an irreversible or constant current.
Electric field applied on charge
In current electricity class 12 notes, Imagine a small area perpendicular to the charge flow. Both positive and negative charges can flow through this region in the forward or backward direction. Suppose the net forward positive current flowing through this region in a time interval is q, (ie the difference between the forward and backward).
Similarly, suppose the net forward negative current flowing through this region is q_. Then in this time interval t is the net charge flowing through this region. For a constant current, it is directly proportional to t and the quotient defines the electric current flowing in the forward direction through the field It = Q. (If this number is negative, it gives an indication that the current is in a backward direction.) The electric current is not always irreversible, so more broadly, we define electric current as follows.
Suppose the net charge flowing through the cross-section of a conductor in the time interval At is Ag. Then the electric current flowing through this transverse cut of the conductor at time t is defined as the value of the ratio of Ag or At with the limits of Attending towards zero.
Electric field applied on charge
In current electricity class 12 notes, If an electric field is applied to an electric charge, it will experience a force. If it is free to move, it will also move and generate electric current. Like the upper level of the atmosphere, called the ionosphere, free charged particles are found in nature. However, the negatively charged electrons and positively charged electrons in molecules and atoms are not free to move due to their bonding with each other. The gross matter is made up of many molecules, for example, one gram of water contains about 1022 molecules.
These molecules are so clustered that the electron is no longer attached to an individual nucleus. Electrons are still bound in some materials, that is, they are not accelerated even when applied electric fields. In some other substances, especially in metals, some electrons are free to move realistically within the material. In these materials, commonly called conductors, an electric current is generated by applying an electric field.
If we consider the solid conductor, in fact, these atoms are closely bound in you, due to which the charged electrons carry the electric current. However, there are other types of conductors, such as electrical decomposition solutions, in which both positive and negative charges can move. We will focus our discussion on solid conductors in which negatively charged electrons carry electric current in the background of stable cations.
Let us first consider a situation where no electric field is present. Electrons interact with bonded ions while doing thermal motions. After electron impact