Page 67 - Schaum's Outline of Theory and Problems of Electric Circuits

ANALYSIS METHODS
56

Fig. 4-31 (cont.) [CHAP. 4

25
I T ¼ ¼ 5A
5
Now the branch currents can be obtained by working back through the circuits of Fig. 4-31(b) and
4-31(a)
1
I C ¼ I F ¼ I T ¼ 2:5A
2
1
I D ¼ I E ¼ I C ¼ 1:25 A
2
3 5
I A ¼ I T ¼ A
6 þ 3 3
6 10
I B ¼ I T ¼ A
6 þ 3 3
4.16 Find the value of the adjustable resistance R which results in maximum power transfer across the
terminals ab of the circuit shown in Fig. 4-32.

Fig. 4-32

0
0
First a The ´ venin equivalent is obtained, with V ¼ 60 V and R ¼ 11
. By Section 4.10, maximum
0
power transfer occurs for R ¼ R ¼ 11
, with
V 02
P max ¼ ¼ 81:82 W
4R 0

Supplementary Problems

4.17 Apply the mesh current method to the network of Fig. 4-33 and write the matrix equations by inspection.
Obtain current I 1 by expanding the numerator determinant about the column containing the voltage sources
to show that each source supplies a current of 2.13 A.