Short notes
Objective questions (Answers are given below)
- The method of symmetrical components is
very useful for
(a) solving unbalanced polyphase circuits
(b) analysing the performance of 3-phase
electrical machinery
(c) calculating currents resulting from
unbalanced faults
(d) all of the above - An unbalanced system of 3-phase voltages
having RYB sequence actually consists of
(a) a positive-sequence component
(b) a negative-sequence component
(c) a zero-sequence component
(d) all of the above. - The zero-sequence component of the
unbalanced 3-phase system of vectors VA, VB
and VC is …. of their vector sum.
(a) one-third (b) one-half
(c) two-third (d) one-fourth - In the case of an unbalanced star-connected
load supplied from an unbalanced 3- φ , 3
wire system, load currents will consist of
(a) positive-sequence components
(b) negative-sequence components
(c) zero-sequence components
(d) only (a) and (b).
1.(d) 2. (d) 3. (a) 4. (d)