What is the formula for calculating power in a DC circuit?

• A. P = V + I
• B. P = V * I
• C. P = V / I
• D. P = I / V

Answer: (B)

The correct formula for calculating power in a DC circuit is derived from the relationship between voltage (V), current (I), and power (P). In a DC circuit, power is defined as the rate at which electrical energy is transferred by an electric circuit. The formula that captures this relationship is P = V * I, where power (P) is measured in watts, voltage (V) is measured in volts, and current (I) is measured in amperes.

This formula indicates that power is the product of the voltage across a circuit element and the current flowing through it. When you multiply these two quantities, you obtain the total power being consumed or delivered by that element. This concept is fundamental to understanding how electrical devices operate and how electricity is utilized in various applications, confirming that power increases with either a rise in voltage or current.

The other options do not represent the correct relationship for power in a DC circuit; thus, they cannot accurately describe the power calculation in a simple DC context. The distinction is crucial for proper analysis and applications of electrical systems.