Static Electricity Name: Insulators, Conductors and Polarization Read from Lesson 1 of the Static Electricity chapter at The Physics Classroom: http://www.physicsclassroom.com/Class/estatics/u811d.html http://www.physicsclassroom.com/Class/estatics/u8lie.html MOP Connection: Static Electricity: preface to sublevels 5 - 7 1. Insulators are different than conductors in that insulators a. do not contain electrons or protons b. do not contain any charge c. have a weaker affinity for electrons d. do not allow charge to freely move 2. Materials through which electrons can move readily are classified as a. conductors b. insulators c. semi-conductors 3 The diagram at the right shows a metal sphere attached to the top of an insulating stand. The metal sphere contains an excess of electrons and is thus charged. A student holds various objects in her hand and touches the object to the sphere. Which of the following objects below would allow charge to throw it when the student touches the object to the sphere? a. a plastic straw b. a piece of paper c. a steel house key d. a metal paper clip e. a strip of aluminum foil Consider these two spheres. They have both been charged. In one case the charge is isolated in three distinct locations; in the other case, the excess charge is even distributed about the surface of the sphere. Which one of these spheres is made of an insulating material and which is made of a conducting material? Label which is which and support your answer with an explanation. 5. TRUE or FALSE: Conductors cannot be charged by frictional rubbing. Explain your answer. 6. A balloon is charged by rubbing it with animal fur. It is then pressed against a wooden cabinet. The balloon and cabinet attract, seeming to defy the force of gravity, This attraction is best explained by a. induction charging of the wood b. frictional charging of the wood c, polarization of wood molecules d. polarization of balloon molecules The above effect (in question #6) is most often noticed of a, conductors b, insulators c. charged objects The Physics Classroom, 2020 Page 7