PHY 182 1st Edition Lecture 15Outline of Last Lecture I. Charges in an Electric FieldII. Electric dipolesOutline of Current Lecture I. Background to Gauss's LawII. Calculating Electric FluxCurrent LectureBackground of Gauss's Law- If you know the electric field, you can use Gauss's Law to find the charge distribution.- Outward electric flux = the electric field lines are directed outward from an object- Inward electric flux = the electric filed lines are directed inward toward an object- Electric flux is very similar to fluid flow. To understand how to calculate flux, we can look at how to calculate fluid flow.- For a fluid flowing through a rectangular surface that is perpendicular to the direction the fluid is moving, the volume per time that passes through the surface can be calculated as the velocity of the fluid multiplied by the area of the surface.- If the surface is tilted in an orientation such that less fluid is flowing though it, you must take this tilt angle into consideration when calculating the new volume flow rate. The equation is now a dot product of velocity and area, which means that you must multiply it by cosine of the tilt angle.- To write an equation as a dot product, both quantities must be vectors. So we must choose a direction to assign to the surface area (since it does not usually have an associated direction). We choose this associated direction to be perpendicular to the surface.Calculating Electric FluxThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- For a surface in a uniform electric field, the electric flux is the magnitude of the electric field multiplied by the area of surface (if it is a flat surface and the direction of the field isperpendicular to the object).- If the surface is tilted, the flux becomes equivalent to the dot product of the electric fieldvector and the surface area vector.- The general definition of electric flux is that it equals the surface integral of the electric field vector multiplied by dA.- It is important to remember that the electric flux through a closed surface is proportional to the total electric charge inside the surface.- When finding the electric flux of a closed surface, the flux is independent of size and shape. It depends only on the amount of contained charge.- If the electric field lines are going into the surface, it corresponds to negative electric flux.- If the electric field lines are going out of the surface, it corresponds to positive electric flux.- If there is no charge inside of a closed surface, the net flux is
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