# direct and alternating current

## direct current

When current flows in just one direction, it is called direct current (DC). The diagram below shows how direct current flows through a simple circuit. An example of direct current is the current that flows through a battery- powered flashlight. In addition to batteries, solar cells and fuel cells can also provide direct current.

## alternating current

When current keeps reversing direction, it is called alternating current (AC). You can see how it works in the two diagrams below. The current that comes from a power plant and supplies electricity to homes and businesses is alternating current. The current changes direction 60 times per second. It happens so quickly that the light bulb doesnt have a chance to stop glowing when the reversals occur. Q: Which type of current flows through the wires in your home? A: Alternating current from a power plant flows through the wires in a home.

## instructional diagrams

No diagram descriptions associated with this lesson

## questions

direct current is provided by

``````a) batteries.

b) fuel cells.

c) solar cells.

-->  d) all of the above
``````

power plants in the u.s. supply direct current to homes and businesses.

``````a. true

-->  b. false
``````

the electric current that flows through a flashlight is alternating current.

``````a. true

-->  b. false
``````

if you live in the u.s., the type of current that flows through the wires inside the walls of your home is alternating current.

``````-->  a. true

b. false
``````

which of the following devices uses direct current?

``````a) microwave oven

-->  b) solar-powered calculator

c) electric toaster

d) two of the above
``````

## diagram questions

No diagram questions associated with this lesson