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Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.
Reason (R): True power is the real part of (VI).
  • a)
    Both A and R are true and R is the correct explanation of A.
  • b)
    Both A and R are true but R is not the correct explanation of A.
  • c)
    A is true but R is false.
  • d)
    A is false but R is true.
Correct answer is option 'D'. Can you explain this answer?
Verified Answer
Assertion (A): In an alternating circuit, if the current is (4 - j3) a...
V = (100 - j50) volt,
I = (4 - j3) A
∴ S = VI* = (100 - j50)(4 - j3)*
= (100 - j50)(4 + j3)
= 550 + j100
∴ P= 100 W and Q = 100 VAR
Q is in VAR not in VA. Hence, assertion is not correct.
Also P is the real part of apparant power (S= VI).
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Most Upvoted Answer
Assertion (A): In an alternating circuit, if the current is (4 - j3) a...
Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.

Reason (R): True power is the real part of (VI).

To determine if the assertion and reason are correct, let's analyze each statement separately.

Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.

To calculate the reactive power, we need to find the complex power (S) first. The complex power is given by the product of the voltage (V) and the complex conjugate of the current (I*).

Given:
Current (I) = 4 - j3 A
Impressed Voltage (V) = 100 - j50 V

Complex Power (S) = V * I*
= (100 - j50) * (4 + j3)
= 400 + 300j - 200j - 150
= 250 + 100j

The complex power (S) consists of two components: the real power (P) and the reactive power (Q). The real power is the real part of the complex power, and the reactive power is the imaginary part of the complex power.

Real Power (P) = Re(S)
= Re(250 + 100j)
= 250 VA

Reactive Power (Q) = Im(S)
= Im(250 + 100j)
= 100 VAR

The reactive power in the circuit is 100 VA, which contradicts the assertion. Therefore, Assertion (A) is false.

Reason (R): True power is the real part of (VI).

The reason states that true power is the real part of (VI). This is a correct statement.

True Power (P) = Re(VI)

However, the reason does not provide any explanation or justification for why the reactive power in the circuit is 100 VA. Therefore, Reason (R) is not the correct explanation of Assertion (A).

In conclusion, both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A). Hence, the correct answer is option 'D'.
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Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.Reason (R): True power is the real part of (VI).a)Both A and R are true and R is the correct explanation of A.b)Both A and R are true but R is not the correct explanation of A.c)A is true but R is false.d)A is false but R is true.Correct answer is option 'D'. Can you explain this answer?
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Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.Reason (R): True power is the real part of (VI).a)Both A and R are true and R is the correct explanation of A.b)Both A and R are true but R is not the correct explanation of A.c)A is true but R is false.d)A is false but R is true.Correct answer is option 'D'. 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 Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.Reason (R): True power is the real part of (VI).a)Both A and R are true and R is the correct explanation of A.b)Both A and R are true but R is not the correct explanation of A.c)A is true but R is false.d)A is false but R is true.Correct answer is option 'D'. 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 Assertion (A): In an alternating circuit, if the current is (4 - j3) amperes and the impressed voltage is (100 - j50) volts, the reactive power in the circuit is 100 VA.Reason (R): True power is the real part of (VI).a)Both A and R are true and R is the correct explanation of A.b)Both A and R are true but R is not the correct explanation of A.c)A is true but R is false.d)A is false but R is true.Correct answer is option 'D'. Can you explain this answer?.
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