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Conceptual Physics. Notes on Chapter 33 Electric Fields & Potential. Electric Fields & Potential. “ May the FORCE be with you ”. Electric Fields & Potential. All particles have an electric field around them. A electric field is a kind of aura that extends outward through space.
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Conceptual Physics Notes on Chapter 33 Electric Fields & Potential
Electric Fields & Potential “May the FORCE be with you”
Electric Fields & Potential • All particles have an electric field around them. A electric field is a kind of aura that extends outward through space.
Electric Fields & Potential • To show the effects of the electric field, we use a “small test charge” (which is positive) to determine the direction and strength of the field.
Electric Fields & Potential • To show the effects of the electric field, we use a “small test charge” (which is positive) to determine the direction and strength of the field.
Electric Fields & Potential • Since the field has magnitude and direction it is a vector and can be represented with vectors. • These vectors are called Field lines or Lines of force • (See fig. 33.3 pg. 519)
Electric Fields & Potential • Where these force lines are close together, the force is strong. Where the lines are farther apart, the force is weaker.
Electric Fields & Potential Electric Shielding: • Because of mutual repulsion, electrons move as far apart as possible. On a hollow object, the interior will have NO CHARGE OR FIELD. The force on a test charge inside a hollow sphere will cancel to Zero
Electric Fields & Potential • On odd shaped objects, the chargeinside is still zero, but not uniform on the outside.
Electric Fields & Potential Electric Potential Energy: • Remember chapter 8 when you lifted an object --- you did work on that object. The same thing applies here. • A test charge has Potential Energy by virtue of its position.
Electric Fields & Potential • If the test charge is “let go”, the potential energy will be transferred into kinetic energy of movement.
Electric Fields & Potential Electric Potential = Electric potential energy Charge 1 Volt = 1 Joule_____ 1 Coulomb • Note --- The voltage of a balloon rubbed on your head can be very high. But the electric potential energy is low because of the small amount of charge.
Electric Fields & Potential Storage of Energy: • Electrical energy can be stored in a common device called a capacitor.
Electric Fields & Potential • A capacitor is a devise that has two plates separated by a small distance and connected to a battery. • Note --- this can be a Shocking experience if you are the discharging path !