Chapter 11 glossary terms

A closed path along which electrons that are powered by an energy source can flow.

A source of energy that generates and electric current by chemical reactions involving to different metals or metal compounds separated by a solution that is a conductor.

A connection of two or more cells.

One or two of the metal terminals in a cell or battery.

The breakdown of an electrode is one factor that can limit the life of the cell.

A solution or paste that conducts charge.

A cell that contains an electrolyte that is a paste. 

A cell that contains a liquid electrolyte. 

A cell that can be used only once.

A cell that can be recharged.

A cell that generates electricity through the chemical reactions of fuel that is stored outside the cell. 

- Hydrogen fuel cell combines hydrogen that is stored in a tank or cartridge with oxygen from the air

- By-products are heat and water

A device that converts solar radiation into electricity.

A point of connection for closing an electric circuit.

A switch is a control device. It is a conductor that can complete or break the circuit it is . connected to.

Electrons do  not flow through any part of a circuit where there is a gap or break. Opening a switch creates a gap, and any device that is connected to the switch will stop working. An open circuit is one in which there is a gap or break in the circuit.

Electric current refers to the rate of movement of electric charge. In an electric circuit, the current is due to the flow of electrons.

The unit of electric charge is the coulomb and one coulomb (C) is the quantity of charge that is equal to the charge of 6.25 x 10¹⁸ electrons.

The unit of electric current is the ampere (A). A current of 1.0 A in a circuit means that 1.0 C of charge passes through a given point in a circuit in a second. Electric current is measured using an ammeter.

The free electrons in a solid, move when an electric field is produced by a cell. The electrons do not get very far before colliding with ions or other electrons in a solid. The collisions interfere with the flow of electrons. Electrical resistance is a property of substance that hinder the electric current and converts electrical energy to other forms of energy.

A resistor is used to decrease the current by specific amount.Metals have a lower resistance than non-metals.

When electrons collide with metal ions, some energy is converted into heat. A load is a resistor or any other device that transforms electric energy into heat, motion, sound, or light.

The voltage of a cell is related to the amount of work that is done on each coulomb of charge that moves between the terminals of the cell.

V=1 J/C

A cell marked 1.5 V will do 1.5 J of work moving a coulomb of electrons from the negative terminal, through the circuit, and to the positive terminal.

A diagram that uses standard symbols to represent the components in an electric circuit and their connections.

A circuit in which there is only one path along which electrons can flow.

A circuit in which there is more than one path along which electrons can flow.

The ratio of potential difference to current is a constant called resistance.

• V=IR
• I=V/R
• R=V/I

Resistance is measured in ohms.

A conductor in which there is no resistance.

Something that doesn't obey ohm's law.

Ex. A light bulb doesn't obey ohm's law because the greater the resistance the larger the current is.

Loads right after one another in a series circuit.

Loads behind after one another in a parallel circuit.