Explore topic-wise MCQs in Network Theory Questions and Answers.

This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Network Theory Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.

1.

If a star connected system has equal impedances Z1, then after converting into delta connected system having equal impedances Z2, then?

A. Z2 = Z1
B. Z2 = 2Z1
C. Z2 = 3Z1
D. Z2 = 4Z1
Answer» D. Z2 = 4Z1
Discussion
2.

A symmetrical three-phase, three-wire 440V supply is connected to star-connected load. The impedances in each branch are ZR = (2+j3) Ω, ZY = (1-j2) Ω, ZB = (3+j4) Ω. Find ZBR.

A. (5.22-j0.82) Ω
B. (-3.02+j8) Ω
C. (-5.22+j0.82) Ω
D. (3.8-j0.38) Ω
Answer» C. (-5.22+j0.82) Ω
Discussion
3.

A symmetrical three-phase, three-wire 440V supply is connected to star-connected load. The impedances in each branch are ZR = (2+j3) Ω, ZY = (1-j2) Ω, ZB = (3+j4) Ω. Find ZBY.

A. (-5.22+j0.82) Ω
B. (5.22-j0.82) Ω
C. (3.8-j0.38) Ω
D. (-3.02+j8) Ω
Answer» C. (3.8-j0.38) Ω
Discussion
4.

A symmetrical three-phase, three-wire 440V supply is connected to star-connected load. The impedances in each branch are ZR = (2+j3) Ω, ZY = (1-j2) Ω, ZB = (3+j4) Ω. Find ZRY.

A. (5.22-j0.82) Ω
B. (-3.02+j8) Ω
C. (3.8-j0.38) Ω
D. (-5.22+j0.82) Ω
Answer» D. (-5.22+j0.82) Ω
Discussion
5.

If the resistors of star connected system are ZR, ZY, ZB then the impedance ZBR in delta connected system will be?

A. (ZRZY + ZYZB + ZBZR)/ZY
B. (ZRZY + ZYZB + ZBZR)/R
C. (ZRZY + ZYZB + ZBZR)/ZB
D. (ZRZY + ZYZB + ZBZR)/(ZB+ZR)
Answer» B. (ZRZY + ZYZB + ZBZR)/R
Discussion
6.

If the resistors of star connected system are ZR, ZY, ZB then the impedance ZBY in delta connected system will be?

A. (ZRZY + ZYZB + ZBZR)/(ZB+ZY)
B. (ZRZY + ZYZB + ZBZR)/ZB
C. (ZRZY + ZYZB + ZBZR)/ZY
D. (ZRZY + ZYZB + ZBZR)/ZR
Answer» E.
Discussion
7.

If the resistors of star connected system are ZR, ZY, ZB then the impedance ZRY in delta connected system will be?

A. (ZRZY + ZYZB + ZBZR)/ZB
B. (ZRZY + ZYZB + ZBZR)/ZY
C. (ZRZY + ZYZB + ZBZR)/ZR
D. (ZRZY + ZYZB + ZBZR)/(ZR+ZY)
Answer» B. (ZRZY + ZYZB + ZBZR)/ZY
Discussion
8.

If a resistor ZR is connected between R and N, ZBR between R and B, ZRY between R and Y and ZBY between B and Y form a delta connection, then after transformation to star, the impedance at B is?

A. (ZBRZBY)/(ZRY+ZBY+ZBR)
B. (ZRYZBY)/(ZRY+ZBY+ZBR)
C. (ZBY)/(ZRY+ZBY+ZBR)
D. (ZBR)/(ZRY+ZBY+ZBR)
Answer» B. (ZRYZBY)/(ZRY+ZBY+ZBR)
Discussion
9.

If a resistor ZR is connected between R and N, ZBR between R and B, ZRY between R and Y and ZBY between B and Y form a delta connection, then after transformation to star, the impedance at Y is?

A. (ZRY)/(ZRY+ZBY+ZBR)
B. (ZBY)/(ZRY+ZBY+ZBR)
C. (ZRYZBY)/(ZRY+ZBY+ZBR)
D. (ZRYZBR)/(ZRY+ZBY+ZBR)
Answer» D. (ZRYZBR)/(ZRY+ZBY+ZBR)
Discussion
10.

If a resistor ZR is connected between R and N, ZBR between R and B, ZRY between R and Y and ZBY between B and Y form a delta connection, then after transformation to star, the impedance at R is?

A. (ZBRZBY)/(ZRY+ZBY+ZBR)
B. (ZRYZBR)/(ZRY+ZBY+ZBR)
C. (ZRYZBY)/(ZRY+ZBY+ZBR)
D. (ZRY)/(ZRY+ZBY+ZBR)
Answer» C. (ZRYZBY)/(ZRY+ZBY+ZBR)
Discussion