Electric Charges and Fields is covered in Unit -1 Electrostatics in Physics Class 12. According to the new CBSE syllabus for the Class 12 board exam, unit 1 is worth 8 points. This chapter focuses on mathematical computations and intellectual comprehension. You should also be aware that the Class 12 Physics board exam includes 3-4 numerical questions for 10-15 points. To do so, you’ll need to be familiar with all of the principles of electric charges and fields. According to the most recent information, Unit-1 has an importance of 9% in the NEET exam. 2 to 3 questions with a weightage of 8-12 percent are anticipated to appear in the JEE Main test. This subject is more important in board examinations and competitive entrance tests. The, electric charges and fields class 12 notes PDF can assist you in better understanding this subject. As a result, Chapter 1 of Class 12 Physics is separated into two sections: Electric Charges and Electric Fields.
Electric Charges and Fields
Charged with electricity The property of matter that allows it to create and experience electric and magnetic effects is called charge.
Insulators and Conductors: Conductors are substances that readily enable the flow of electricity through them, such as metals and the earth, whereas insulators are things that give significant resistance to the passage of electricity, such as plastic rod and nylon.
Frictional electricity is caused through the transfer of electrons.
Charge Additivity is a term that refers to the ability of a substance to Charges are scalars that add up in the same way as real numbers do. It indicates that if a system has n charges.
Charge Conservation An isolated system’s total charge is always conserved, meaning the system’s starting and end charges are the same.
Charge Quantification Charge is quantized because it is a discrete amount rather than a continuous value. Charge on an item is expressed mathematically as q=ne. Where n is an integer and e is the charge on an electron. A physical quantity is said to be quantised when it exists in discrete packets rather than in a continuous amount. As a result, charge is quantified.
Units of Charge
- SI unit coulomb (C)
- CGS system
- electrostatic unit, esu of charge or stat-coulomb (stat-C)
- electromagnetic unit, emu of charge or ab-C (ab-coulomb)
The Law of Coulomb The electrostatic interaction or repulsion force operating between two stationary point charges, according to this definition.
Coulombian forces (electrostatic forces) are conservative forces.
The Electrostatic Forces Superposition Principle The net electric force experienced by a particular charge particle q0 as a result of a system of charged particles is equal to the vector sum of the forces exerted on it by all the other charged particles in the system, according to this concept.
Continuous Charge Distribution Causes Electrostatic Force
Charge distribution is considered to be continuous in a region when charges are tightly separated.
Intensity of the electric field the force experienced per unit positive test charge put at that location without disrupting the source charge is defined as the electric field intensity at any point owing to source charge.
We will apply the principle of superposition to the electric field generated by a system of charges, just as we did with the electrostatic force.
Lines of Electric Field lines are a visual representation of the electric field surrounding a charge arrangement (s). These lines have a positive charge at the beginning and a negative charge at the conclusion. The direction of field at any location is determined by the tangent on these lines.
Dipole Electromagnetic An electric dipole is made up of two-point charges of equal size and opposing nature separated by a little distance.
Moment of an electric dipole the electric dipole moment (p), which is the product of the charge (q) and the spacing between the charges, is used to determine the strength of an electric dipole (2l).
The electric field of an electric dipole is the area around the dipole where the dipole’s electric impact may be felt.
An electric dipole in a uniform electric field produces torque (E).
When the angle between p and E is 0°, the dipole is in stable equilibrium, and when the angle is 180°, it is in unstable equilibrium.
In a homogenous electric field, the net force on an electric dipole is zero.
When an electric dipole is put in a non-uniform electric field, it produces a net force and torque.
Work involved in rotating the dipole from its stable equilibrium point to the position where it receives the most torque.
Charge Quantization: Charge quantization is an attribute in which all free charges are an integral multiple of e, the basic unit of charge.
Additivity of Charges: The algebraic sum of all the individual charges in the system equals the overall charge in the system.
Charge Conservation: In an isolated system, the entire charge is preserved. When you brush the rod with silk, for example, the silk acquires the charge while the rod loses it.
Learn how to solve the question: Which one of the following graphs represents the variation of electric field with distance r from the centre of a charged spherical conductor of radius R?
