1) What will be the value of IC, if Ia1 = 100 ∠ 30° and Ib2 = 20 ∠ 90°?
a. 111.35 ∠ 21.05 °
b. 111.35 ∠ 15.05°
c. 111.35 ∠ 145.06°
d. 111.35 ∠ 158.94°
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Answer
Explanation
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ANSWER: 111.35 ∠ 158.94°
Explanation:
No explanation is available for this question!
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2) Which sequence component is represented by the following phasor?
a. Positive sequence
b. Zero sequence
c. Negative sequence
d. None of these
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Answer
Explanation
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ANSWER: Negative sequence
Explanation:
No explanation is available for this question!
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3) Phase shift of symmetrical components happens in which among the following?
a. Delta - delta
b. Star – delta
c. Delta – star
d. Both (b) and (c)
e. All of these
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Answer
Explanation
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ANSWER: Both (b) and (c)
Explanation:
No explanation is available for this question!
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4) For Y - Δ and Δ - Y transformers, the phase shift between the transformer windings is equal to “ n * 30° “. What does ‘n’ represent in the equation?
a. Number of windings
b. Number of turns
c. Turns ratio
d. Hour number
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Answer
Explanation
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ANSWER: Hour number
Explanation:
No explanation is available for this question!
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5) In the manufacture of transformers, ANSI prescribes certain standards. What is this standard?
a. High voltage side should lead the low voltage side by 30° with Y - Δ or Y - Δ connections.
b. High voltage side should lead the low voltage side by 60° with Y - Δ or Y - Δ connections.
c. High voltage side should lag the low voltage side by 30° with Y - Δ or Y - Δ connections.
d. High voltage side should lag the low voltage side by 60° with Y - Δ or Y - Δ connections.
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Answer
Explanation
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ANSWER: High voltage side should lead the low voltage side by 30° with Y - Δ or Y - Δ connections.
Explanation:
No explanation is available for this question!
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6) What will be the value of IA , if Ia1 = 100 ∠ 30° and Ib2 = 20 ∠ 90°?
a. 111.35 ∠ 21.05 °
b. 99.12 ∠ 73.47 °
c. 135.24 ∠ 23.45 °
d. 63.85 ∠ 21.05 °
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Answer
Explanation
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ANSWER: 111.35 ∠ 21.05 °
Explanation:
No explanation is available for this question!
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7) If the value of Ia = 100∠0° and Ib = 75∠-50° in a three phase three wire system, what will be the value of negative sequence current?
a. 23.12 ∠ -96.02 °
b. 59.12 ∠ -73.47 °
c. 76.21 ∠-84.25 °
d. 41.25 ∠ -36.85 °
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Answer
Explanation
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ANSWER: 59.12 ∠ -73.47 °
Explanation:
No explanation is available for this question!
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8) What is the value of the zero sequence current?
a. 3 times the current in the neutral wire
b. 1 / 3 times the current in the neutral wire
c. √3 times the current in the neutral wire
d. Equal to the current in the neutral wire
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Answer
Explanation
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ANSWER: 1 / 3 times the current in the neutral wire
Explanation:
No explanation is available for this question!
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9) The positive sequence current is always equal to ______________.
a. Always zero
b. 1/3 of the negative sequence current
c. Negative sequence current
d. 3 times the negative sequence current
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Answer
Explanation
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ANSWER: Negative sequence current
Explanation:
No explanation is available for this question!
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10) What is the value of (1+ a + a2)?
a. 0
b. 1
c. -1
d. ∞
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Answer
Explanation
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ANSWER: 0
Explanation:
No explanation is available for this question!
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