What term describes the product of effective voltage and effective current, expressed in Volt-Amps (VA)?

What term describes the product of effective voltage and effective current, expressed in Volt-Amps (VA)?

• A. Real Power
• B. Apparent Power
• C. Reactive Power
• D. Power Factor

Answer: (B)

In AC circuits, the effective (RMS) voltage and current multiply to give the apparent power, measured in volt-amperes (VA). This quantity represents the total power flow in the circuit without regard to how much of it is actually doing useful work versus being momentarily stored and returned each cycle. The real power, in watts, is the portion that does work and equals V_rms I_rms cos φ, where φ is the phase angle between voltage and current. The reactive power, in VAR, reflects energy exchanged with reactive elements and equals V_rms I_rms sin φ. The power factor PF is cos φ, the ratio of real power to apparent power. Since the question asks for the product of effective voltage and current expressed in VA, the term is apparent power.

In AC circuits, the effective (RMS) voltage and current multiply to give the apparent power, measured in volt-amperes (VA). This quantity represents the total power flow in the circuit without regard to how much of it is actually doing useful work versus being momentarily stored and returned each cycle. The real power, in watts, is the portion that does work and equals V_rms I_rms cos φ, where φ is the phase angle between voltage and current. The reactive power, in VAR, reflects energy exchanged with reactive elements and equals V_rms I_rms sin φ. The power factor PF is cos φ, the ratio of real power to apparent power. Since the question asks for the product of effective voltage and current expressed in VA, the term is apparent power.