<p>I just cannot grasp those "A particle of charge q enters a magnetic field, which way will it move" problems... or how the right-hand rule is used... </p>
<p>can someone, like... put the WHOLE idea of Magnetic fields in their own words?</p>
<h2>b u m p</h2>
<p>p n w d</p>
<p>Just remember that the magnetic field acts on a moving charged particle with a force perpendicular to the charged particle's direction of motion. Which direction you say? This is where the right hand rule comes into play. Use the right hand for positive particles and take the opposite directions for negative particles. I use the simplest. Hold your hand flat with your thumb also in the plane of your hand but pointing in a direction perpendicular to the direction of your fingers. Point your fingers in the direction of the magnetic field and your thumb in the direction your charged particle is moving. The force will come out of the palm of your hand (through the back of your hand and out the palm). The force will be opposite for an oppositely charged particle.</p>
<p>Wow thanks for the explanation.
One question though, when you say "hold your hand flat" you means facing up right? As in the inner side of your palm faces upwards?</p>
<p>An alternate way is to point the fingers of your right hand in the direction that the particle is moving, and then curl your fingers toward the direction of the magnetic field. Your outstretched thumb shows you the direction of the force for a positive charge.</p>
<p>Example: a positive charge in the plane of your web browser moves to the right: =======></p>
<p>The magnetic field is up in the plane of your web browser.</p>
<p>The force on the particle is out of the plane of your web browser (right toward your face).</p>
<p>No holding your hand flat means holding it flat in any way but the thumb is perpendicular to the rest of the fingers. Then your fingers point in the direction of the field and your thumb in the direction the charged particle is heading. With that, you'll know how to hold your hand. </p>
<p>Magnetic field coming out of your computer screen, a proton heading downwards. It'll get pushed to the left, where your palm faces.</p>
<p>Magnetic field going into your computer screen, a proton heading left. The magnetic force will push downwards.</p>
<p>Magnetic field going into your computer screen, proton heading into the computer screen. Not possible, no force there.</p>
<p>and remember as the particle changes direction, so does the force on it because the magnetic force is perpendicular</p>