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366 ⏐⏐⏐ NETWORK THEOREMS
E 1
10 V
R 1
12 �
FIG. 9.122
A plot of the power delivered to RL in Fig. 9.120 for a range of values for RL extending from 0 � to 30 �.
R 2
6 �
FIG. 9.123
Problem 1.
R 3
plot generated appears as a listing at the bottom left of the screen as
W(RL).
Before leaving the subject, we should mention that the power to RL
can be determined in more ways than one from the Add Traces dialog
box. For example, first enter a minus sign because of the resulting current
direction through the resistor, and then select V2(RL) followed by
the multiplication of I(RL). The following expression will appear in the
Trace Expression box: V2(RL)*I(RL), which is an expression having
the basic power format of P � V * I. Click OK, and the same power
curve of Fig. 9.122 will appear. Other quantities, such as the voltage
across the load and the current through the load, can be plotted against
RL by simply following the sequence Trace-Delete All Traces-Trace-
Add Trace-V1(RL) or I(RL).
6 �
5 V E 2
PROBLEMS
Th
SECTION 9.2 Superposition Theorem
1. a. Using superposition, find the current through each
resistor of the network of Fig. 9.123.
b. Find the power delivered to R1 for each source.
c. Find the power delivered to R1 using the total current
through R1. d. Does superposition apply to power effects? Explain.