What is the phase relationship between current and voltage for reactive power?
The correct answer is C: They are 90 degrees out of phase. What is the phase relationship between current and voltage for reactive power is that they are 90 degrees out of phase. Reactive power occurs when voltage and current are 90° out of phase. For amateur radio operators, this is important for power calculations. Understanding this helps when calculating power.
Exam Tip
Reactive power phase relationship = current and voltage 90 degrees out of phase. Think 'R'eactive 'P'ower = 'R'equires '9'0° 'P'hase difference. Reactive power occurs when voltage and current are 90° out of phase. Not just out of phase, not in phase, not 45° - just 90°.
Memory Aid
"Reactive power phase relationship = current and voltage 90 degrees out of phase. Think 'R'eactive 'P'ower = '9'0° phase. Reactive power occurs when voltage and current are 90° out of phase. Important for power calculations."
Real-World Application
Reactive power: The phase relationship between current and voltage is that they are 90 degrees out of phase. This is why reactive power doesn't do real work - the voltage and current are perpendicular. This is the relationship - 90° out of phase.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. They are out of phase isn't specific enough - reactive power requires 90° out of phase. Out of phase isn't specific.
Option B: Incorrect. They are in phase isn't correct - reactive power requires 90° out of phase. In phase is wrong.
Option D: Incorrect. They are 45 degrees out of phase isn't correct - reactive power requires 90° out of phase. 45° is wrong.
题目解析
The correct answer is C: They are 90 degrees out of phase. What is the phase relationship between current and voltage for reactive power is that they are 90 degrees out of phase. Reactive power occurs when voltage and current are 90° out of phase. For amateur radio operators, this is important for power calculations. Understanding this helps when calculating power.
考试技巧
Reactive power phase relationship = current and voltage 90 degrees out of phase. Think 'R'eactive 'P'ower = 'R'equires '9'0° 'P'hase difference. Reactive power occurs when voltage and current are 90° out of phase. Not just out of phase, not in phase, not 45° - just 90°.
记忆口诀
Reactive power phase relationship = current and voltage 90 degrees out of phase. Think 'R'eactive 'P'ower = '9'0° phase. Reactive power occurs when voltage and current are 90° out of phase. Important for power calculations.
实际应用示例
Reactive power: The phase relationship between current and voltage is that they are 90 degrees out of phase. This is why reactive power doesn't do real work - the voltage and current are perpendicular. This is the relationship - 90° out of phase.
错误选项分析
Option A: Incorrect. They are out of phase isn't specific enough - reactive power requires 90° out of phase. Out of phase isn't specific. Option B: Incorrect. They are in phase isn't correct - reactive power requires 90° out of phase. In phase is wrong. Option D: Incorrect. They are 45 degrees out of phase isn't correct - reactive power requires 90° out of phase. 45° is wrong.
知识点
Phase relationship, Current and voltage, Reactive power, 90 degrees out of phase
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.