Electrical Engineering (EE) Exam > Electrical Engineering (EE) Questions > If the voltage across and the current into a ...
Start Learning for Free
If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________
- a)positive, positive
- b)negative, negative
- c)negative, positive
- d)positive, negative
Correct answer is option 'A'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Most Upvoted Answer
If the voltage across and the current into a certain load or part of t...
Complex Power:
Considered a circuit in which supply voltage, V ∠α and current, I ∠β and impedance Z,
Complex Power (S) = VI*
S = (V ∠+α) (I ∠-β) = VI ∠(α - β)
Considered, (α - β) = ϕ
S = VI (cos ϕ + j sin ϕ) …. (1)
And, S = P + jQ …. (2)
From equation (1) and (2),
P = VI cos ϕ
Q = VI sin ϕ
The phasor diagram of the circuit can be drawn as,
From the phasor, we can say the load is inductive,
- Inductive load has the property of absorbing reactive power by the load, therefore reactive power (Q) is positive.
- From the phasor it is clear that the voltage leads the current, therefore the phase angle between the voltage and current (α - β) is positive.
Free Test
FREE
| Start Free Test |
Community Answer
If the voltage across and the current into a certain load or part of t...
Understanding Reactive Power
Reactive power (measured in VARs) is a crucial concept in AC circuits, representing the power that alternates between the source and load but does not perform any real work. It arises from the phase difference between voltage and current.
Voltage and Current Representation
- The voltage across the load can be expressed as:
**V = |V|∠α**
- The current into the load is expressed as:
**I = |I|∠β**
Here, α and β are the phase angles of voltage and current, respectively.
Calculating Reactive Power
Reactive power (Q) is calculated as:
**Q = V * I* = |V| * |I| * sin(α - β)**
Where:
- **V** is the voltage magnitude
- **I*** is the complex conjugate of the current
The sine function indicates the significance of the phase angle difference (α - β).
Analyzing the Phase Angles
- When **α - β > 0** (meaning α is greater than β), **sin(α - β)** is positive, resulting in positive reactive power.
- Conversely, when **α - β < 0**,="" it="" yields="" negative="" reactive="" power.="" />
Conclusion: The Correct Answer
In the context of the question:
- If the phase angle **α - β** is positive and the current **|I|** is also positive, it indicates that the circuit is absorbing reactive power, which confirms that the correct answer is:
**a) positive, positive**
This illustrates that the load is primarily inductive, drawing reactive power from the source.
Reactive power (measured in VARs) is a crucial concept in AC circuits, representing the power that alternates between the source and load but does not perform any real work. It arises from the phase difference between voltage and current.
Voltage and Current Representation
- The voltage across the load can be expressed as:
**V = |V|∠α**
- The current into the load is expressed as:
**I = |I|∠β**
Here, α and β are the phase angles of voltage and current, respectively.
Calculating Reactive Power
Reactive power (Q) is calculated as:
**Q = V * I* = |V| * |I| * sin(α - β)**
Where:
- **V** is the voltage magnitude
- **I*** is the complex conjugate of the current
The sine function indicates the significance of the phase angle difference (α - β).
Analyzing the Phase Angles
- When **α - β > 0** (meaning α is greater than β), **sin(α - β)** is positive, resulting in positive reactive power.
- Conversely, when **α - β < 0**,="" it="" yields="" negative="" reactive="" power.="" />
Conclusion: The Correct Answer
In the context of the question:
- If the phase angle **α - β** is positive and the current **|I|** is also positive, it indicates that the circuit is absorbing reactive power, which confirms that the correct answer is:
**a) positive, positive**
This illustrates that the load is primarily inductive, drawing reactive power from the source.
Attention Electrical Engineering (EE) Students!
To make sure you are not studying endlessly, EduRev has designed Electrical Engineering (EE) study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Electrical Engineering (EE).
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Similar Electrical Engineering (EE) Doubts
Top Courses for Electrical Engineering (EE)View all
If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer?
Question Description
If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer?.
If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? for Electrical Engineering (EE) 2024 is part of Electrical Engineering (EE) preparation. The Question and answers have been prepared according to the Electrical Engineering (EE) exam syllabus. Information about If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Electrical Engineering (EE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer?.
Solutions for If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Electrical Engineering (EE).
Download more important topics, notes, lectures and mock test series for Electrical Engineering (EE) Exam by signing up for free.
Here you can find the meaning of If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice If the voltage across and the current into a certain load or part of the circuit are expressed by I = |I|∠β, respectively. Reactive power (VI*) will be ___________ when the phase angle ∠(α - β) and current is __________a)positive, positiveb)negative, negativec)negative, positived)positive, negativeCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Electrical Engineering (EE) tests.
|
|
Explore Courses for Electrical Engineering (EE) exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup