Consider the following statements regarding complex power:1.Apparent power is the magnitude of complex power.2.Reactive power can be negative.3.Power factor is defined as ratio of real power to reactive power.Which of the above statements is/are correct?
⚑ Report issue
Found a wrong answer, translation, image or source problem? Send it to editorial review.
In sinusoidal steady state, complex power combines real and reactive power as S=P+jQ. Power factor is the ratio P/|S| and equals cosφ for sinusoidal voltage and current. Key relation: S=P+jQ; |S|=√(P²+Q²); PF=P/|S|=cosφ.
Exam focus: Draw the power triangle before choosing a power-factor relation. Common trap: Do not confuse P/Q with power factor.
Formula / Key Relation
S=P+jQ; |S|=√(P²+Q²); PF=P/|S|=cosφ.
Detailed Explanation
Correct Answer: A - 1 and 2 only Quick Concept Explanation In sinusoidal steady state, complex power combines real and reactive power as S=P+jQ. Power factor is the ratio P/|S| and equals cosφ for sinusoidal voltage and current. Key relation: S=P+jQ; |S|=√(P²+Q²); PF=P/|S|=cosφ.Exam focus: Draw the power triangle before choosing a power-factor relation. Common trap: Do not confuse P/Q with power factor. Statement-wise Verification Statement 1 - Correct.Apparent power is the magnitude of complex power.Its magnitude |S| is apparent power in VA Statement 2 - Correct.Reactive power can be negative.Inductive loads conventionally have positive Q and capacitive loads negative Q.…
Correct Answer: A - 1 and 2 only
Quick Concept Explanation
In sinusoidal steady state, complex power combines real and reactive power as S=P+jQ. Power factor is the ratio P/|S| and equals cosφ for sinusoidal voltage and current. Key relation: S=P+jQ; |S|=√(P²+Q²); PF=P/|S|=cosφ.
Exam focus: Draw the power triangle before choosing a power-factor relation. Common trap: Do not confuse P/Q with power factor.
Statement-wise Verification
Statement 1 - Correct. Apparent power is the magnitude of complex power. Its magnitude |S| is apparent power in VA
Statement 2 - Correct. Reactive power can be negative. Inductive loads conventionally have positive Q and capacitive loads negative Q.
Statement 3 - Incorrect. Power factor is defined as ratio of real power to reactive power. The correct principle is: Power factor is the ratio P/|S| and equals cosφ for sinusoidal voltage and current.
Core Concept
In sinusoidal steady state, complex power combines real and reactive power as S=P+jQ. Its magnitude |S| is apparent power in VA, while P is measured in W and Q in var. Inductive loads conventionally have positive Q and capacitive loads negative Q. Power factor is the ratio P/|S| and equals cosφ for sinusoidal voltage and current.
Formula / Key Relationship
S=P+jQ; |S|=√(P²+Q²); PF=P/|S|=cosφ.
Why the Other Options Are Wrong
Option B is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2. Option D is incorrect because it includes incorrect statement(s) 3.
Exam Shortcut / Approach
Draw the power triangle before choosing a power-factor relation.
Common Mistake
Do not confuse P/Q with power factor.
Quick Revision
Complex Power and Power Factor is linked with Complex Power, AC Fundamentals and Basic Electrical Engineering. Draw the power triangle before choosing a power-factor relation.
Quick Trick
Draw the power triangle before choosing a power-factor relation.
Why Other Options Are Wrong
Option B is incorrect because it includes incorrect statement(s) 3 and omits correct statement(s) 1. Option C is incorrect because it omits correct statement(s) 2. Option D is incorrect because it includes incorrect statement(s) 3.
Common Mistake
Do not confuse P/Q with power factor.
Exam Tip
Draw the power triangle before choosing a power-factor relation.
SEO + Knowledge GraphRelated PYQs & Exam ContextExam path, knowledge path and deeper practice links.
