Solution Found!
83. The current through the 20-11 resistor in Fig. 19-68
Chapter 19, Problem 83(choose chapter or problem)
The current through the \(20-\Omega\) resistor in Fig. 19-68 docs not change whether the two switches \(\mathbf{S}_{1}\) and \(\mathbf{S}_{2}\) are both open or both closed. Use this clue to determine the value of the unknown resistance R.
Questions & Answers
QUESTION:
The current through the \(20-\Omega\) resistor in Fig. 19-68 docs not change whether the two switches \(\mathbf{S}_{1}\) and \(\mathbf{S}_{2}\) are both open or both closed. Use this clue to determine the value of the unknown resistance R.
ANSWER:Step 1 of 4
From the circuit below, it is obvious that the current that passes through the 20 -ohm resistor is the full current drawn from the battery when the two switches are opened.
Now we need to find the equivalent resistance of these in-series resistors.
\(\begin{array}{l}
R_{e q}=50+20+10\\
R_{e q}=80 \Omega \text {.... Equation(1) }
\end{array}\)