19.1 Introduction to Magnetic Fields and Forces | General Physics

Chad provides an introduction to Magnetic Fields and Forces in this lesson. He begins by drawing the magnetic field lines of a simple bar magnet, comparing them to the electric field lines around an electric dipole. He then describes the Earth's magnetic field and explains why the poles of a magnet are called North and South poles. The rest of the lesson is devoted to describing and defining the magnetic force acting on a charged particle in motion. The formula for this magnetic force is provided and described: F=qvBsin(theta). Chad explains how if the magnetic field and the velocity of the charged particle are either parallel or antiparallel, then the magnetic force is zero, and that the magnetic force is at a maximum when the magnetic field and the particle's velocity are perpendicular to each other. He also explains that this formula is the result of a cross product, and therefore that the direction of the magnetic force will be perpendicular to both the magnetic field and the velocity of the charged particle. The right-hand rule is introduced which allows for the determination of the direction of the magnetic force. The right hand rule is presented for both positive and negative charges, and several examples are solved. The lesson is concluded with a magnetic force practice problem in which both the magnitude and direction of the magnetic force on a charged particle in motion are solved for. 00:00 Lesson Introduction 00:51 Magnetic Field Lines 04:14 Earth's Magnetic Field 08:19 Magnetic Force on a Charged Particle in Motion 12:47 Right Hand Rule #1 17:39 Right Hand Rule Practice 20:25 Magnetic Force Calculation Practice Problem Check out Chad's General Physics Master Course: https://www.chadsprep.com/physics-youtube