Problem 10-18 Source:
Problem 3.23 - page 65 - O'MALLEY, John - Book: Análise de Circuitos - 2ª ed. - Coleção Schaum - Ed. Makron Books - 1994.
Find the value of Vab over the open circuit as shown in the
circuit show in Figure 10-18.1.
Solution of the Problem 10-18
Note that as terminals a-b are open, current will not flow through resistors
10 Ω and 50 Ω. Soon, there will be no voltage drop on them.
In this case, there will be only the current I circulating through the circuit, as indicated by the orange arrow on the Figure 10-18.1. Then we can calculate the value of the current I, or:
With this value it is possible to calculate Vcx, then:
The next step is to determine the value of Vab. But of the circuit, we have:
However, we know that Vac = 30 volts, Vcx = 60 volts and Vxb = - 10 volts. Therefore, replacing these values in the above equation, we find:
