CHAP. 4]

4.3

49

ANALYSIS METHODS

Solve the network of Problems 4.1 and 4.2 by the node voltage method.

See Fig. 4-19.

With two principal nodes, only one equation is necessary. V1  60 V1 V1 V1 þ þ ¼0 þ 12 6 12 7 from which V1 ¼ 18 V.

Then, I1 ¼

60  V1 ¼ 6A 7

Fig. 4-19

4.4

In Problem 4.2, obtain Rinput;1 and use it to calculate I1 . Rinput;1 ¼

Then

4.5

R 2880 2880 ¼ ¼ 10  ¼ 288 11  18 6   6 18  I1 ¼

60 60 ¼ 6A ¼ Rinput;1 10

Obtain Rtransfer;12 and Rtransfer;13 for the network of Problem 4.2 and use them to calculate I2 and I3 . The cofactor of the 1,2-element in R must include a negative sign:    12 6   ¼ 216 12 ¼ ð1Þ1þ2  0 18 

Rtransfer;12 ¼

R 2880 ¼ 13:33  ¼ 216 12

Then, I2 ¼ 60=13:33 ¼ 4:50 A:    12 18   ¼ 72 13 ¼ ð1Þ1þ3  0 6 

Rtransfer;13 ¼

R 2880 ¼ ¼ 40  13 72

Then, I3 ¼ 60=40 ¼ 1:50 A:

4.6

Solve Problem 4.1 by use of the loop currents indicated in Fig. 4-20. The elements in the matrix form of the equations are obtained by inspection, following the rules of Section 4.2.

Mahmood_Nahvi_eBook_Schaum_s_Outlines_Theory_An
Mahmood_Nahvi_eBook_Schaum_s_Outlines_Theory_An