مصادر الحقل المغناطيسي ١ الحقل الناجم عن شحنة متحركة

Peace be upon you, and God's mercy and blessings. We move on to the second chapter, which is sources of the magnetic field. At the beginning of the chapter, there is a small and easy concept we want to discuss and take an example of. The first concept is the magnetic field produced by a moving

charge. What is the formula that gives me the magnetic field produced by a moving charge? And how do I determine the direction of this field? First, let's write down the formula. It equals , it equals 4 pi. Or mu naught over 4 pi. Mu naught over 4 pi. Of course, you all know mu naught. Mu naught is 4 pi

times 10 to the power of -7, so mu naught over 4 pi times q v cross r, the unit vector, over r squared. What do these symbols represent? What does each one of them mean? And how do we calculate and determine the direction of the field? This is what we will learn in this video, in addition to an

example of this formula. So, initially, I want to assume that I have a moving charge to be able to show you what the formula's meanings are. Let's assume I have a positive charge moving in this direction; this is the velocity vector of the charge, v. And I have a point in the vicinity of the charge; this point,

for example, point B, I will call it. How do I determine the field produced by the charge q, q, arbitrary? The point. I will draw a line connecting from the charge to the point. This line . The first thing you need to pay attention to is the r squared in the denominator. r is the distance from the

charge to the point. That's how we know where we get r from. A second thing is the unit vector r, regarding its direction; the unit vector r points from the charge to the point. It is essentially a unit vector, so its magnitude is one. Meaning, there is no need to think about calculating it. A