Network theory miscellaneous


  1. Assuming ideal elements in the circuit shown below, the voltage Vab will be—











  1. View Hint View Answer Discuss in Forum

    The given circuit:

    Applying KVL in the loop, we get,
    Vab – 2 × 1 + 5 = 0
    or
    Vab = 2 – 5
    = – 3V.

    Correct Option: A

    The given circuit:

    Applying KVL in the loop, we get,
    Vab – 2 × 1 + 5 = 0
    or
    Vab = 2 – 5
    = – 3V.


  1. In figure, the value of the source voltage is—











  1. View Hint View Answer Discuss in Forum

    The given figure

    Applying KCL at node C, we get

    =
    VC - 0
    = 1 + 2
    10

    or
    VC = 30V
    and
    =
    Vs - VC
    = 2
    10

    or
    VS = 20 + Vc = 20 + 30
    = 50V
    Hence alternative (C) is the correct choice.

    Correct Option: C

    The given figure

    Applying KCL at node C, we get

    =
    VC - 0
    = 1 + 2
    10

    or
    VC = 30V
    and
    =
    Vs - VC
    = 2
    10

    or
    VS = 20 + Vc = 20 + 30
    = 50V
    Hence alternative (C) is the correct choice.



  1. In figure, the value of R is—











  1. View Hint View Answer Discuss in Forum

    The given circuit:

    Applying KCL at node C,

    =
    VC - VA
    +
    VC - VB
    +
    VC
    = 0
    1412

    or
    Vc
    1
    +
    1
    +
    1
    =
    VA
    +
    VB
    =
    100
    +
    40
    1412141141

    or
    Vc
    1 + 14 + 7
    =
    100 + 40 × 14
    1414

    or
    VC = 30V
    Now, current in 14Ω resistor,
    I14Ω =
    100 - VC
    =
    100 - 30
    1414

    = 5A
    So,
    IR = 10 – 5 = 5A
    and
    R =
    VA - VB
    =
    100 - 40
    IR5

    or
    R = 60/5 ≈ 12Ω
    Hence alternative (D) is most correct choice.

    Correct Option: A

    The given circuit:

    Applying KCL at node C,

    =
    VC - VA
    +
    VC - VB
    +
    VC
    = 0
    1412

    or
    Vc
    1
    +
    1
    +
    1
    =
    VA
    +
    VB
    =
    100
    +
    40
    1412141141

    or
    Vc
    1 + 14 + 7
    =
    100 + 40 × 14
    1414

    or
    VC = 30V
    Now, current in 14Ω resistor,
    I14Ω =
    100 - VC
    =
    100 - 30
    1414

    = 5A
    So,
    IR = 10 – 5 = 5A
    and
    R =
    VA - VB
    =
    100 - 40
    IR5

    or
    R = 60/5 ≈ 12Ω
    Hence alternative (D) is most correct choice.


  1. The voltage V for the network shown below is always equal to—











  1. View Hint View Answer Discuss in Forum

    The given circuit:

    From above figure
    V – 4 – 5 = 0
    or
    V = 9 V
    Hence alternative (A) is the correct choice.

    Correct Option: A

    The given circuit:

    From above figure
    V – 4 – 5 = 0
    or
    V = 9 V
    Hence alternative (A) is the correct choice.



  1. In the circuit shown in the figure, the value of the current i will be given by—











  1. View Hint View Answer Discuss in Forum

    The given circuit:

    Va = 5 ×
    1
    =
    5
    V
    1 + 12

    Vb = 4Vab ×
    1
    =
    Vab
    1 + 34

    Vab = Va – Vb = 5/2 – Vab
    or
    2Vab = 5/2
    or
    Vab = 5/4 V
    or
    Vab = 1.25 V
    and
    i =
    4 × Vab
    =
    4 × 1.25
    = 1.25A
    44

    Hence alternative (B) is the correct choice.

    Correct Option: A

    The given circuit:

    Va = 5 ×
    1
    =
    5
    V
    1 + 12

    Vb = 4Vab ×
    1
    =
    Vab
    1 + 34

    Vab = Va – Vb = 5/2 – Vab
    or
    2Vab = 5/2
    or
    Vab = 5/4 V
    or
    Vab = 1.25 V
    and
    i =
    4 × Vab
    =
    4 × 1.25
    = 1.25A
    44

    Hence alternative (B) is the correct choice.