Direct current

Definition

Direct current (DC) is a type of electrical current where the flow of electric charge is unidirectional. It is commonly used in batteries, electronics, and other applications requiring a stable and constant voltage.

5 Must Know Facts For Your Next Test

1. Direct current flows in only one direction, from the positive to the negative terminal.
2. DC is typically produced by sources such as batteries, solar cells, and DC generators.
3. Ohm's Law ($$V = IR$$) applies to direct current circuits for calculating voltage, current, and resistance.
4. In a DC circuit, the voltage remains constant over time if the load remains unchanged.
5. Many electronic devices use DC because it provides consistent power without the fluctuations seen in alternating current (AC).

Review Questions

• What are common sources of direct current?
• How does Ohm's Law apply to direct current circuits?
• Why do many electronic devices prefer using direct current?

Related terms

Alternating Current (AC):

A type of electrical current where the flow of electric charge periodically reverses direction.

Voltage:

The electric potential difference between two points; measured in volts.

Resistance:

$$R = \frac{V}{I}$$; measures how much an object opposes the passage of an electric current.