1. Electric Charge

Electric charge is a fundamental property of matter that causes it to experience a force when placed in an electric and magnetic field. There are two types of electric charges:

• Positive Charge: The type of charge carried by protons.
• Negative Charge: The type of charge carried by electrons.

Properties of Electric Charge:

• Like charges repel each other, and opposite charges attract each other.
• Charge is conserved, meaning the total charge in an isolated system remains constant.
• Charge is quantized, which means it exists in discrete amounts, typically multiples of the charge of an electron (1.6 × 10⁻¹⁹ C).

2. Coulomb’s Law

Coulomb’s Law describes the force between two point charges:
F=kq1​q2/r2​​

• F is the force between the charges.
• k is Coulomb’s constant (8.99×109 N•m2/C2)
• q₁ and q₂ are the magnitudes of the charges.
• r is the distance between the charges.

Coulomb’s Law shows that the force between charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.

3. Electric Field

The electric field (( E )) is a vector field that represents the force exerted on a positive test charge placed in the field. It is defined as the force per unit charge.
E=q/F​

• E is the electric field.
• F is the force experienced by the test charge.
• q is the magnitude of the test charge.

The direction of the electric field is the direction in which a positive test charge would move.

Units of Electric Field: The SI unit of the electric field is newtons per coulomb (N/C).

4. Electric Field Due to Point Charge

The electric field due to a point charge is given by:
E=k∣q∣/r2​

• q is the charge creating the field.
• r is the distance from the charge to the point where the field is being measured.

The direction of the electric field is radially outward for positive charges and radially inward for negative charges.

5. Electric Field Lines

Electric field lines are a visual representation of the electric field. They show the direction of the force that would act on a positive test charge.

• The lines originate from positive charges and terminate at negative charges.
• The density of the lines indicates the strength of the electric field (more lines = stronger field).
• Electric field lines never cross.

6. Electric Dipole

An electric dipole consists of two equal and opposite charges separated by a distance. The electric field due to a dipole at a point in space depends on the distance and angle from the dipole.

Conclusion

Electric charges create electric fields, and these fields exert forces on other charges. Understanding electric charges and fields is crucial in various areas of physics, from electrostatics to electromagnetism, and is foundational for studying electrical circuits and more complex phenomena.