Magnetic Fields 1 and 2

Study Notes

Magnetism involves forces produced by magnets that attract or repel objects.
Magnetic fields are vector fields influencing moving electric charges, currents, and magnetic materials.
Magnetic materials, like iron and nickel, align with magnetic field lines, which run from North to South.
The density of magnetic field lines indicates the strength of the magnetic field.
Magnetic fields are symbolized by 𝑩 and measured in Teslas (𝑻).

Attraction occurs when magnetic flux lines point in the same direction; repulsion occurs when they are opposite.
A moving electric charge in a wire generates a magnetic field that wraps around perpendicularly to the current's direction.
The right-hand rule helps determine the direction of the magnetic flux lines.

Magnetic Field Strength (B) is calculated using the formula:
- 𝑩 = 𝝁𝟎 𝑰 / (𝟐𝝅 𝒓)
Variables include:
- 𝝁𝟎: magnetic constant (4𝜋 × 10^(-7) T m/A)
- 𝑰: current through the wire
- 𝒓: distance from the wire

A solenoid is an electromagnet formed by winding a coil of wire, producing a uniform magnetic field.
Stacking loops amplifies the magnetic field due to the contributions of each loop.

A charged particle in a magnetic field experiences a force that alters its motion based on charge direction and magnetic field orientation.
The right-hand "slap" rule is used to find the direction of movement for positively charged particles.
Magnetic Force (F) depends on:
- 𝒒: particle charge
- 𝑩: magnetic field strength
- 𝒗: particle velocity
- 𝜽: angle between particle path and field
The formula for magnetic force is:
- 𝑭 = 𝒒 𝒗 𝑩 𝐬𝐢𝐧 𝜽
Maximum force occurs when the particle moves perpendicularly to the field (sin 90 = 1).
Minimal force happens when the particle travels parallel to the field (sin 0 = 0).

Current-carrying wires, composed of moving charged particles, experience magnetic force in external magnetic fields.
The magnetic force on wires can be derived from the magnetic force equation:
- 𝑭 = 𝑩 𝑰 𝑳 𝐬𝐢𝐧 𝜽
𝑳 represents the length of the wire.