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

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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

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