Electric circuits miscellaneous


Electric circuits miscellaneous

  1. The voltage VC1, VC2 and VC3 across the capacitors in the circuit in the given figure, under steady state are respectively










  1. View Hint View Answer Discuss in Forum

    In steady state, capacitors are open and inductances are short.

    For VC1

    VC1 = 100 ×
    40
    = 80 V
    50

    For VC2 and VC3
    VC2 = 80 ×
    C3
    C2 + C3

    = 80 ×
    3
    = 48 V
    5

    VC3 = 80 ×
    C2
    C2 + C3

    = 16 × 2 = 32 V

    Correct Option: B

    In steady state, capacitors are open and inductances are short.

    For VC1

    VC1 = 100 ×
    40
    = 80 V
    50

    For VC2 and VC3
    VC2 = 80 ×
    C3
    C2 + C3

    = 80 ×
    3
    = 48 V
    5

    VC3 = 80 ×
    C2
    C2 + C3

    = 16 × 2 = 32 V


  1. When the angular frequency ω in the given figure is varied from 0 to ∞ , the locus of the current phasor I2 is given by









  1. View Hint View Answer Discuss in Forum

    I2(ω) =
    Em cosωt
    R2 +
    1
    jωC



    At ω = ∞ , I2ω =
    Em
    R2

    Also, I2 is leading with voltage phasor.
    At ω = 0, I2 (0) = 0
    Thus desired locus should be as shown.

    Correct Option: A

    I2(ω) =
    Em cosωt
    R2 +
    1
    jωC



    At ω = ∞ , I2ω =
    Em
    R2

    Also, I2 is leading with voltage phasor.
    At ω = 0, I2 (0) = 0
    Thus desired locus should be as shown.



  1. The circuit shown in the given figure in resonates at










  1. View Hint View Answer Discuss in Forum

    Input impedance of the circuit,

    Z = 10 +
    1
    || 4jω +
    1


    = 10 +
    [1 - 4ω2]
    jω[2 - 4ω2]

    Correct Option: B

    Input impedance of the circuit,

    Z = 10 +
    1
    || 4jω +
    1


    = 10 +
    [1 - 4ω2]
    jω[2 - 4ω2]


  1. For the circuit show in the (given figure) i(t) under steady state is










  1. View Hint View Answer Discuss in Forum

    d.c. voltage 5V would encounter an open circuit in the capacitor and hence the current is 0.

    For a.c , i(t) =
    10 sin t
    1 + j2 +
    1
    j

    =
    10 sin t
    =
    10
    sin (t - 45°)
    1 + j2

    = 7.07 sin (t – 45°)

    Correct Option: D

    d.c. voltage 5V would encounter an open circuit in the capacitor and hence the current is 0.

    For a.c , i(t) =
    10 sin t
    1 + j2 +
    1
    j

    =
    10 sin t
    =
    10
    sin (t - 45°)
    1 + j2

    = 7.07 sin (t – 45°)



  1. Switch S in the given figure is closed at t = 0. If v2 (0) = 10 V and vg (0) = 0 V respectively, voltage across the capacitors in steady state will be










  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: D

    NA