1) What is the fault current expression in case of LLG faults?
a. I f = 3 I a1
b. I f = 0
c. I f = 3 I a0
d. I f = I a1
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Answer
Explanation
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ANSWER: If = 3 Ia0
Explanation:
No explanation is available for this question!
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2) How are the zero sequence and negative sequence networks connected in case of LLG faults?
a. Parallel
b. Series
c. Can be connected in either way
d. Such type of connection does not exist
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Answer
Explanation
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ANSWER: Parallel
Explanation:
No explanation is available for this question!
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3) What is the expression for the current Ia2, if a double line to ground fault occurs on an unloaded generator through fault impedance?
a. I a2 = - I a1 * (Z 0 + 3Z f) / ( Z 0 + Z 2 + 3Z f)
b. I a2 = - I a1 * (Z 0 + 3Z f + Z 2) / ( Z 0 + Z 2 + 3Z f)
c. I a2 = - I a0 * (Z 0 + Z f) / ( Z 0 + Z 2 + 3Z f)
d. I a2 = - I a1 * Z 2 * (Z 0 + 3Z f) / ( Z 0 + Z 2 + 3Z f)
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Answer
Explanation
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ANSWER: Ia2 = - Ia1 * (Z0 + 3Zf) / ( Z0 + Z2 + 3Zf)
Explanation:
No explanation is available for this question!
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4) What is the value of fault current If, if the neutral grounding is absent in LLG fault?
a. I f = - 3 Ia1 ( Z 2 / Z 2 + Z 1)
b. I f = 0
c. I f = √3 * (E a / Z 1 + Z 2 + Z 0)
d. I f = 3 * (E a / Z 1 + Z 2 + Z 0)
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Answer
Explanation
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ANSWER: If = 0
Explanation:
No explanation is available for this question!
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5) What will be the value of current Ia, if the fault occurs between the lines B, C and ground?
a. I a = 1
b. I a = 0
c. I a = ∞
d. I a = - (I b + I c )
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Answer
Explanation
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ANSWER: Ia = 0
Explanation:
No explanation is available for this question!
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6) What percentage of fault occurring in the power system is LLG fault?
a. 20 %
b. 30 %
c. 5 %
d. 10 %
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Answer
Explanation
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ANSWER: 10 %
Explanation:
No explanation is available for this question!
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