2223 la vida despues de la muerte es vida o muerte, Resúmenes de Derecho

¡Descarga 2223 la vida despues de la muerte es vida o muerte y más Resúmenes en PDF de Derecho solo en Docsity! 650 Chapter 16 Electric Potential Figure 16.40 The potential is constant inside a metal in equilibrium. EXAMPLE Solution Checkpoint 10 Show that if you are very far from the ring (z > R), the potential is approximately equal to that of a point charge. (This is to be expected, because if you are very far away, the ring appears to be nearly a point.) Potential Inside a Conductor at Equilibrium In a previous section we noted that because the net electric field is zero inside a metal object in equilibrium, the potential difference between any two locations inside the metal must be zero. Since this is true, we can conclude that the potential at any location inside the metal must be the same as the potential at any other location (Figure 16.40). In a conductor in equilibrium the potential is exactly the same everywhere inside the conductor, because E = 0 inside the conductor. AV=-(E¿Ax+ EyAy+E¿Az) =0 so V is constant. QUESTION Does this mean that the potential is zero at every location inside a metal in equilibrium? No. The potential inside a metal object in equilibrium is constant (the same at every location), but it need not be zero. Charges on the surface of the metal object or on other objects may contribute to a nonzero but uniform potential inside the metal. The Potential Inside a Charged Metal Sphere A solid metal sphere of radius R has a charge of Q uniformly distributed over its surface. What is the potential (relative to infinity) throughout the sphere? At any distance r > R, the potential relative to infinity due to the charged sphere is Fm 2, so the potential relative to infinity just outside the surface of 0 e 1 : . ; the sphere is ha 2. Inside the sphere the electric field is zero everywhere, so 0 the potential difference between any location inside the sphere and the surface : o 2 1 is zero. Therefore the potential inside the sphere is a everywhere. TEO This situation is a good example of the indirect relationship between field and potential. Inside the sphere the electric field is zero everywhere but the electric potential is nonzero everywhere. Avoiding a Common Confusion A common error is to assume that the electric field at a location determines the potential at a location. In fact, the electric field at location A has very little to do with the potential at location A! Similarly, the electric field at A and the electric field at B have very little to do with the potential difference between locations A and B; itis the electric field in the intervening region that determines AV. As we have just scen, the electric field due to a charged spherical shell is zero inside the shell, but the potential inside the shell due to the charges on the sphere is nonzero.