Definitions [3]
What are free electrons?
FREE ELECTRONS. Electrons of the outermost orbit of a solid, which can easily leave the atom and become free to move inside the solid are called FREE ELECTRONS
What do you mean by conservation of charges?
According to the Law of conservation of charge
“When two different bodies are rubbed together, both bodies get charged equally but with charges of the opposite kind.” Thus, the total charge of two bodies before and after rubbing remains the same.
Example: When an ebonite rod is rubbed with fur, the electrons from the fur are transferred to the ebonite rod and therefore the ebonite rod becomes negatively charged (due to gain of electrons), while the fur becomes equally positively charged (due to deficit of a same number of electrons). As the same no. of electrons are, exchanged by the ebonite rod and fur, the magnitude of charges main same but with opposite sign.
Electric charge is an intrinsic property of certain fundamental particles (like electrons and protons) that gives rise to electric and magnetic forces, causing them to experience a force when placed in an electromagnetic field.
OR
Electric charge is the physical property of matter that causes it to experience a force when placed in an electric field.
Key facts:
- SI Unit: Coulomb (C)
- Dimensional Formula: [A T] (Ampere × Time)
- Two types exist: positive and negative
Key Points
- Law of Conservation of Charge: Charge can neither be created nor destroyed; it can only be transferred from one body to another.
- Additivity: If a system has charges q1, q2, q3, ... qn, the total charge is:
Q = q1 + q2 + q3 + ... +qn
Analogy: Think of charge like money in a closed economy — it only moves between accounts (bodies); no new "charge currency" is printed or destroyed.
