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Alternating Current Analysis 291


ANALYTICAL Solution

The circuit of Figure 3.71 is transformed into the phasor circuit diagram shown in
Figure 3.72.
The three loop equations are

() (^1020) **
1
20
jIII  123  20   0 50 0





 ∠
  20 20 30  
1
40
1
40
Ij 12   IjI 30











  • *
    0
    1
    40
    10
    1
    40
    Ij I12 3   jI 945 







    

  • * ∠
    The matrix loop equation is given by
    (^) ()(/)
    ( (/)) (/)
    (/ )
    10 20 1 20 20 0
    20 20 30 1 40 1 40
    0 1 40 10
     
    
    
    j
    jj
    jj((/ )


  • 140
    50
    0
    945
    1
    2
    3
































    I
    I
    I
    
    
    
    C 2 = 4 F
    v 1 (t) = 5 cos (10t) V
    v 2 (t) = 9 cos(10
    t + 45°) V
    I 1 I 2 I 3
    R 1 = 10 Ω R 3 = 10 Ω
    R 2 = 20 Ω
    C 1 = 2 F L 1 = 3 H
    FIGURE 3.71
    Network of Example 3.14.
    5 0 ° V 9 45 ° V
    Xc1 = −j(1/20) Ω XL = j 30 Ω
    Xc2 = −j(1/40) Ω
    I 1 I 2 I 3
    R 1 = 10 Ω
    R 2 = 20 Ω
    R 3 = 10 Ω
    FIGURE 3.72
    Phasor circuit diagram of Example 3.14.



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