Power System - II (3150911) MCQs

MCQs of Symmetrical Components

Showing 21 to 30 out of 33 Questions
1 2 3 4
21.
The symmetrical components are used in the fault analysis because
(a) The number of equations becomes smaller
(b) The sequence networks do not have mutual coupling
(c) The sequence networks are  mutually coupled
(d) Results are required in terms of symmetrical components
Answer:

Option (b)

22.
The value of expression 1 + α + α2
(a) 0
(b) 1
(c) -1
(d) 2
Answer:

Option (a)

23.
In the case of balanced 3 phase current,  zero sequence component of current is
(a) Minimum
(b) Maximum
(c) Zero
(d) None of above
Answer:

Option (a)

24.
Zero sequence component in 3 phase voltage of delta is
(a) Line voltage
(b) Zero
(c) √3 line voltage
(d) Line voltage/3
Answer:

Option (b)

25.
In a star connected system without neutral grounding, zero sequence currents are
(a) Zero
(b) Phasor sum  of phase current
(c) Same as RMS value of phase current
(d) Same as peak value of phase current
Answer:

Option (a)

26.
A balanced three phase system consists of
(a) Zero sequence current only
(b) Positive sequence current only
(c) Negative sequence current only
(d) Zero, negative and positive sequence current
Answer:

Option (b)

27.
Positive sequence current of a transmission line is
(a) Always zero
(b) One third of negative sequence current
(c) Equal to negative sequence current
(d) Three times the negative sequence current
Answer:

Option (c)

28.
An unbalanced system of three phase voltage having RYB sequence actually consists of
(a) A positive sequence component
(b) A negative sequence component
(c) A zero sequence component
(d) All of above
Answer:

Option (d)

29.
In case of an unbalanced star connected load supplied from an unbalanced 3 phase, 3 wire system, load current will consist of
(a) Positive sequence components
(b) Negative sequence components
(c) Zero sequence components
(d) Only (a) and (b)
Answer:

Option (d)

30.
For an unbalanced fault with paths for zero sequence currents at the point of fault
(a) Negative sequence and zero sequence voltages are minimum
(b) Negative sequence and zero sequence voltages are maximum
(c) Negative sequence voltage is minimum and zero sequence voltage is maximum
(d) Negative sequence voltage is maximum and zero sequence voltage is minimum
Answer:

Option (b)

Showing 21 to 30 out of 33 Questions
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