Table of Contents

1. Introduction to Electromagnetism

   • Definition and Historical Development
   • Importance in Modern Science and Technology

2. Basic Concepts of Electromagnetism

   • Electric Charge and Electric Fields
   • Magnetic Poles and Magnetic Fields
   • The Relationship Between Electricity and Magnetism

3. Electrostatics

   • Coulomb’s Law
   • Electric Potential and Potential Energy
   • Capacitance and Capacitors

4. Electric Current and Circuits

   • Types of Currents: DC and AC
   • Ohm’s Law and Resistance
   • Series and Parallel Circuits
   • Power in Electric Circuits

5. Magnetism

   • Magnetic Fields and Their Properties
   • Magnetic Materials (Diamagnetic, Paramagnetic, Ferromagnetic)
   • Earth’s Magnetic Field

6. Electromagnetic Induction

   • Faraday’s Law and Lenz’s Law
   • Applications: Transformers and Generators

7. Maxwell’s Equations

   • Overview of Maxwell’s Four Equations
   • Implications for Electromagnetic Waves

8. Electromagnetic Waves

   • The Electromagnetic Spectrum
   • Properties and Applications of Electromagnetic Waves

9. Applications of Electromagnetism

   • Electrical Devices (Motors, Generators)
   • Communication Systems
   • Magnetic Storage and Imaging

10. Circuits in Depth

    • RC, RL, and RLC Circuits
    • Kirchhoff’s Laws
    • Practical Circuit Components (Diodes, Transistors)

11. Advanced Topics in Electromagnetism

    • Quantum Electrodynamics
    • Special Relativity and Electromagnetism
    • Superconductivity

12. Real-World Examples and Experiments

    • Everyday Applications
    • Laboratory Experiments

13. Summary and Key Takeaways

14. Glossary of Terms

1. Introduction to Electromagnetism

Definition and Historical Development

Electromagnetism is the study of electric and magnetic fields and their interactions. It combines two previously distinct fields of study: electricity and magnetism.

Historical Milestones:

• Discovery of static electricity by the ancient Greeks.
• Development of Coulomb’s law and the concept of electric fields in the 18th century.
• Michael Faraday’s work on electromagnetic induction in the 19th century.
• James Clerk Maxwell’s unification of electricity and magnetism into Maxwell’s equations.

Importance

Electromagnetism underpins most modern technologies, including communication systems, power generation, and electronic devices.

2. Basic Concepts of Electromagnetism

Electric Charge

• Positive and negative charges, measured in coulombs ($C$).
• Like charges repel; unlike charges attract.

Electric Fields ($E$)

• A region around a charge where other charges experience a force.
• Defined as E=FqE = \frac{F}{q}E=qF​, where $F$ is force, and $q$ is the charge.

Magnetic Fields ($B$)

• Produced by moving charges or magnetic materials.
• Represented by field lines, where the density indicates field strength.

Electricity and Magnetism Relationship

• Moving electric charges generate magnetic fields.
• Changing magnetic fields induce electric currents.

3. Electrostatics

Coulomb’s Law

• The force ($F$) between two point charges is: F=keq1q2r2F = k_e \frac{q_1 q_2}{r^2}F=ke​r2q1​q2​​ where kek_eke​ is Coulomb’s constant.

Electric Potential (V)

• Work done per unit charge to move a charge in an electric field.
• V=WqV = \frac{W}{q}V=qW​, measured in volts (V).

Capacitance and Capacitors

• Capacitors store energy in electric fields.
• Capacitance ($C$) is C=QVC = \frac{Q}{V}C=VQ​, measured in farads (F).

4. Electric Current and Circuits

Types of Current

• Direct Current (DC): Flows in one direction.
• Alternating Current (AC): Changes direction periodically.

Ohm’s Law

$$V=IR$$

where $V$ is voltage, $I$ is current, and $R$ is resistance.

Series and Parallel Circuits

• Series: Resistors are in a line; total resistance Rt=R1+R2+…R_t = R_1 + R_2 + \dotsRt​=R1​+R2​+….
• Parallel: Resistors share connections; 1/Rt=1/R1+1/R2+…1/R_t = 1/R_1 + 1/R_2 + \dots1/Rt​=1/R1​+1/R2​+….

5. Magnetism

Magnetic Fields

• Represented as $B$, measured in teslas (T).

Types of Magnetic Materials

• Diamagnetic: Weakly repelled by magnets.
• Paramagnetic: Weakly attracted.
• Ferromagnetic: Strongly attracted (e.g., iron).

Earth’s Magnetic Field

• Protects Earth from solar wind.
• Causes phenomena like auroras.

6. Electromagnetic Induction

Faraday’s Law

• A changing magnetic field induces an electric current.

Lenz’s Law

• The induced current opposes the change that created it.

7. Maxwell’s Equations

1. Gauss’s Law: Electric field flux equals charge enclosed.
2. Gauss’s Law for Magnetism: Magnetic monopoles don’t exist.
3. Faraday’s Law of Induction: Relates changing magnetic fields to induced electric fields.
4. Ampère’s Law: Magnetic fields are produced by electric currents and changing electric fields.

8. Electromagnetic Waves

Electromagnetic Spectrum

• Includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Applications

• Wireless communication, medical imaging, and remote sensing.

9. Applications of Electromagnetism

Motors and Generators

• Convert electrical energy to mechanical energy and vice versa.

Communication Systems

• Use electromagnetic waves to transmit data.

10. Circuits in Depth

RC, RL, and RLC Circuits

• Study of circuits with resistors, capacitors, and inductors.

Kirchhoff’s Laws

• Current Law: Total current entering a junction equals total current leaving.
• Voltage Law: Sum of voltages in a loop equals zero.

11. Advanced Topics

Quantum Electrodynamics (QED)

• Explains the interaction between light and matter.

Special Relativity and Electromagnetism

• Unifies electric and magnetic fields in moving frames.

12. Real-World Examples

1. Electrical Appliances: Fans, refrigerators.
2. Transportation: Maglev trains.
3. Healthcare: MRI machines.