# Unit 4: Moving charges and magnetism

## About Course

Course Title: Exploring Moving Charges and Magnetism

Course Description:

Unit 4: Moving Charges and Magnetism explores the fundamental principles governing the interaction between moving charges and magnetic fields. Through theoretical instruction, laboratory experiments, and practical demonstrations, students will explore concepts such as magnetic fields, magnetic force on moving charges, magnetic field due to currents, and electromagnetic induction. The unit will cover different types of magnetic interactions, their characteristics, and the applications of moving charges and magnetism in physics, engineering, and everyday life.

Course Outline:

1. Introduction to Magnetism

– Overview of magnetism: phenomenon of attraction or repulsion between magnetic materials

– Magnetic poles and magnetic fields: regions of space where magnetic forces are experienced

– Magnetic materials: ferromagnetic, paramagnetic, and diamagnetic materials

– Magnetic field lines: visual representation of magnetic field direction and strength

2. Magnetic Force on Moving Charges

– Lorentz force law: mathematical expression describing the magnetic force on a moving charge (F = qvB sinθ)

– Magnetic force direction: direction of force perpendicular to both velocity and magnetic field direction

– Force on a current-carrying wire: magnetic force experienced by a wire carrying electric current

– Applications of magnetic force in particle accelerators, mass spectrometers, and magnetic resonance imaging (MRI)

3. Magnetic Fields Due to Currents

– Biot-Savart law: mathematical expression describing the magnetic field produced by a current-carrying conductor

– Magnetic field direction around a straight wire, circular loop, and solenoid

– Ampère’s law: relationship between magnetic field and electric current in a closed loop

– Applications of magnetic fields due to currents in electromagnets, motors, and generators

4. Magnetic Force on Current-Carrying Wires

– Magnetic force between current-carrying conductors: attraction or repulsion between wires carrying currents

– Magnetic torque on current loops: rotational force experienced by current loops in magnetic fields

– Applications of magnetic force between current-carrying wires in circuit breakers, relays, and transformers

– Magnetic levitation: suspension of objects using magnetic forces in magnetic levitation trains and maglev systems

5. Magnetic Materials and Magnetic Properties

– Magnetic susceptibility: measure of a material’s ability to become magnetized in an external magnetic field

– Ferromagnetic materials: materials with strong magnetic properties, such as iron, nickel, and cobalt

– Hysteresis and magnetic domains: behavior of ferromagnetic materials in changing magnetic fields

– Applications of magnetic materials in magnetic storage devices, sensors, and magnetic resonance imaging (MRI)

6. Electromagnetic Induction

– Faraday’s law of electromagnetic induction: induction of electromotive force (emf) in a conductor due to a changing magnetic field (ε = -ΔΦ/Δt)

– Lenz’s law: direction of induced current opposes the change in magnetic flux causing it

– Self-induction and mutual induction: induction phenomena in solenoids and transformer coils

– Applications of electromagnetic induction in generators, transformers, and electrical power generation

7. Inductance and Inductors

– Inductance: property of an electrical circuit to oppose changes in current flow

– Inductors: passive electrical components designed to store energy in a magnetic field

– Calculation of inductance for solenoids, toroids, and inductor coils

– Applications of inductors in filters, oscillators, and energy storage systems

8. Magnetic Fields in Matter

– Magnetization and magnetic susceptibility of materials: response of materials to external magnetic fields

– Magnetic field inside and outside magnetized materials: behavior of materials in magnetic fields

– Paramagnetism, diamagnetism, and ferromagnetism: magnetic properties of materials at atomic and macroscopic scales

– Applications of magnetic materials in magnetic resonance imaging (MRI), magnetic recording, and magnetic separation

Course Delivery:

The course will be delivered through a combination of lectures, laboratory experiments, demonstrations, and multimedia presentations. Real-world examples and practical applications will be integrated into the curriculum to illustrate the relevance of moving charges and magnetism concepts. Computer simulations and visualization tools may also be used to enhance learning and comprehension.

Assessment:

Student learning will be assessed through quizzes, laboratory reports, homework assignments, midterm exams, and a final examination. Evaluation criteria will include understanding of moving charges and magnetism concepts, proficiency in solving problems, and ability to apply principles to analyze real-world phenomena. Regular feedback and opportunities for hands-on experience will be provided to support student learning and mastery of the material.

Prerequisites:

Students enrolling in this course should have a basic understanding of electric charges and fields, as well as algebra and basic calculus. Familiarity with fundamental concepts of physics, such as forces and energy, is recommended but not required. A strong willingness to engage in problem-solving and critical thinking is essential for success in this course.

By the end of Unit 4, students will have developed a solid understanding of moving charges and magnetism, and their applications in various fields of physics and engineering. They will be proficient in analyzing magnetic interactions, interpreting magnetic properties, and applying magnetic principles to solve problems related to electromagnetism, electric motors, and magnetic materials.