BASIC CONCEPTS

PROBLEMS 21
1.20 Determine the amount of power absorbed or supplied
by the element in Fig. P1.20 if
(a) V 1 = 9 V and I = 2A
(b) V 1 = 9 V and I =-3A
(c) V 1 =-12 V and I = 2A
(d) V 1 =-12 V and I =-3A
+
V 1
-
Figure P1.20
1.21 Calculate the power absorbed by element A in
Fig. P1.21.
I
3 A
1.24 Element B in the diagram in Fig. P1.24 supplies 60 W of
power. Calculate I x .
Figure P1.24
–
24 V B
+
I x
1.25 Element B in the diagram in Fig. P1.25 supplies 72 W of
power. Calculate V A .
3 A
+
V A B
–
–
15 V A
+
Figure P1.21
Figure P1.25
1.26 Element B in the diagram in Fig. P1.26 supplies 72 W of
power. Calculate I x .
1.22 Calculate the power supplied by element A in Fig. P1.22.
2 A
+
20 V A
–
Figure P1.26
+
18 V B
–
I x
Figure P1.22
1.23 Element A in the diagram in Fig. P1.23 absorbs 30 W of
power. Calculate V x .
1.27 (a) In Fig. P1.27 (a), P 1 = 36 W. Is element 2 absorbing
or supplying power, and how much?
(b) In Fig. P1.27 (b), P 2 =-48 W. Is element 1 absorbing
or supplying power, and how much?
2 A
+
V x A
–
+
1 12 V
–
+
2 6 V
-
-
1 6 V
+
+
2 24 V
-
Figure P1.23
(a)
Figure P1.27
(b)