electricity current

electric current

(I, ampere, A) a flow of charge through a conductor

electrochemical cell

A device that transforms chemical energy into electrical energy.

Describe the motion of charges from one terminal of a battery to the other through a flashlight

Electrons move away from the negative terminal of the battery and travel through the filament in the light bulb. They heat the filament, causing it to give off light. The electrons then travel toward the positive terminal of the battery.

If the voltage across a flashlight bulb is 3 V and the bulb's resistance is 6 ohms

I=v/r=3V/6ohms =

If the current in a certain resistor is 6.2 A and the voltage across the resistor is 110 V, what is the resistance of the resistor?

R=V/I = 110 V/6.2 A = 18 ohms

electrical resistance

Slows the movement of charges through a material. It is found as a ratio between the voltage across it and the current through it. R=V/I. Measured in ohms.

Recent discoveries have led some scientists to hope that a material will be found that is superconducting at room temperature. Why would such a material be useful?

Such a material would enable people to use devices that rely on extremely efficient conductors of electricity (such as Maglev trains) without having to cool the conducting material to extremely cold temperatures.

electrical potential energy

The amount of energy of a charged particle in an electric field solely dependent on the particle's position

potential difference

The difference in electrical potential energy between two places in an electrical field.

What quantities are needed to calculate an object's resistance?

To calculate resistance, you need to know the voltage across the object and the current.

Identify which of the following could produce a current: a. a wire connected across a battery's terminals, b. two electrodes in a solution of positive and negative ions., c. a salt crystal whose ions cannot move, d. a sugar-water mixture.

a,b

Predict which way a positive charge will move between two positions of different electrical potential energy, one high and one low. a. from low to high, b. from high to low, c. back and forth between high and low.

b

Classify the following materials, as conductors or insulators: wood, paper clip, glass, air, paper, plastic, steel nail, and rubber.

wood--insulator paper clip conductor glass insulator air--insulator paper insulator plastic insulator steel nail conductor rubber insulator