Chapter 18 Electric Forces and Electric Fields 18

• Slides: 9

Chapter 18 Electric Forces and Electric Fields

18. 1 The Origin of Electricity Total charge: where coulombs

18. 1 The Origin of Electricity Example 1 A Lot of Electrons How many electrons are there in one coulomb of negative charge?

18. 1 The Origin of Electricity Example 1 A Lot of Electrons How many electrons are there in one coulomb of negative charge?

18. 1. 1. A brass key has a net positive charge of +1. 92 10 16 C. Approximately, how many electrons must be added to the key to make it electrically neutral? a) 770 b) 960 c) 1200 d) 1800 e) 2100

18. 2 Charged Objects and the Electric Force It is possible to transfer electric charge from one object to another. The body that loses electrons has an excess of positive charge, while the body that gains electrons has an excess of negative charge.

18. 2 Charged Objects and the Electric Force Or Silk Or glass LAW OF CONSERVATION OF ELECTRIC CHARGE During any process, the net electric charge of an isolated system remains constant (is conserved).

18. 2. 1. Complete the following statement: When a glass rod is rubbed with silk cloth, the rod becomes positively charged as a) negative charges are transferred from the rod to the silk. b) negative charges are transferred from the silk to the rod. c) positive charges are created on the surface of the rod. d) positive charges are transferred from the silk to the rod. e) positive charges are transferred from the rod to the silk.

18. 2 Charged Objects and the Electric Force Like charges repel and unlike charges attract each other.