Define the term “power factor” in AC circuits.

Define the term “power factor” in AC circuits.

• A. The ratio of voltage to current in a circuit
• B. The ratio of real power to apparent power
• C. The ratio of energy consumed to energy produced
• D. The ratio of reactive power to real power

Answer: (B)

Power factor is defined as the ratio of real power to apparent power in an alternating current (AC) circuit. Real power, measured in watts, represents the actual power consumed by the circuit to do useful work, while apparent power, measured in volt-amperes (VA), is the product of the circuit's voltage and current without considering the phase difference between them. By understanding this ratio, one can assess the efficiency of the power being used. A power factor of 1 (or 100%) indicates that all the energy supplied by the source is being utilized efficiently, resulting in optimal performance of electrical systems. If the power factor is less than 1, it suggests that not all the power is effectively being transformed into useful work, which is often caused by the presence of reactive power in the system. In contrast, other definitions provided in the options, such as the ratio of voltage to current, the ratio of energy consumed to energy produced, or the ratio of reactive power to real power, do not accurately capture the specific concept of power factor, further emphasizing the correctness of identifying it as the ratio of real power to apparent power.

Power factor is defined as the ratio of real power to apparent power in an alternating current (AC) circuit. Real power, measured in watts, represents the actual power consumed by the circuit to do useful work, while apparent power, measured in volt-amperes (VA), is the product of the circuit's voltage and current without considering the phase difference between them.

By understanding this ratio, one can assess the efficiency of the power being used. A power factor of 1 (or 100%) indicates that all the energy supplied by the source is being utilized efficiently, resulting in optimal performance of electrical systems. If the power factor is less than 1, it suggests that not all the power is effectively being transformed into useful work, which is often caused by the presence of reactive power in the system.

In contrast, other definitions provided in the options, such as the ratio of voltage to current, the ratio of energy consumed to energy produced, or the ratio of reactive power to real power, do not accurately capture the specific concept of power factor, further emphasizing the correctness of identifying it as the ratio of real power to apparent power.