Electromagnetism Lecture Notes

Magnetic Field Around a Straight Current Carrying Conductor
- A straight conductor carrying electric current generates a magnetic field around it.
Magnetic Field Around a Single Loop (Simple Coil)
- When current flows through a looped conductor, it creates a magnetic field that resembles that of a bar magnet with a north and south pole.
Magnetic Field Around a Solenoid (Coil/Many Turns)
- A solenoid, which is a coil of wire, produces a magnetic field similar to that of a bar magnet when electric current passes through it. The strength and direction of the field can be controlled by varying the current.

Electromagnetic Induction by Electrical Methods
- The process of inducing a current in a conductor by changing the magnetic field around it.
Charged Particles in a Magnetic Field
- Charged particles experience a force when they move through a magnetic field, leading to circular or helical paths.

Electromagnetism is a branch of physics that deals with the study of electric fields, magnetic fields, and their interactions. It encompasses the phenomena associated with charged particles and the forces exerted by electric and magnetic fields.

Michael Faraday
  - A self-educated English physicist and chemist who discovered that a changing magnetic field through a loop induces an electric current in that loop.
  - Faraday's law of induction: The induced electromotive force (emf) in any closed circuit is equal to the rate of change of the magnetic flux through the circuit.
  - This discovery laid crucial groundwork for the electricity supply industry.

Definition
- A magnetic field is a region in space where ferromagnetic materials experience a force of attraction or repulsion due to the presence of a magnetic field.
Properties
  - It is a vector quantity, possessing both magnitude and direction.
  - Field Lines
    - Magnetic field lines are graphical representations indicating the direction of the magnetic field. They always flow from the north pole to the south pole of a magnet.

Noncontact Force
- Forces that act on an object without physical contact, such as magnetic force, electrostatic force, and gravitational force.
Magnetic Force
- The force exerted by magnets when they attract or repel each other or other ferromagnetic materials.
Electrostatic Force
- The force between charged particles; can be attractive or repulsive based on the nature of the charges.
Gravitational Force
- The force of attraction between two masses.

Definition
  - Materials that are easily magnetized and can retain their magnetism after an external magnetic field is removed.
  - Examples of ferromagnetic materials include:
    - Iron
    - Cobalt
    - Nickel
Magnet Properties
- A magnet always has two poles: a north pole and a south pole, regardless of the size or shape of the magnet.

Magnetic Field Lines
  - Always flow from north to south.
  - Provide a visual representation of the strength and direction of the magnetic field.
  - The density of lines indicates the strength: closer lines = stronger field; further apart lines = weaker field.