Chapter 34, Problem 1PLA

To determine

The true statement about the circuit in Figure 34-5.

Answer to Problem 1PLA

Option (a) and (b) it is a single-loop circuit and assuming $R_1$ and $R_2$ were known the currents could be determined without the use of Kirchhoff’s rules.

Explanation of Solution

Single-loop circuits are circuits that can be reduced to a single resistor in series with power supply. Multi-loop circuits are circuits that cannot be reduced to a single resistor in series with power supply.

Kirchhoff’s current rule states that the sum of current into a junction is equal to the sum of current out of the junction.

Kirchhoff’s voltage rule states that the sum of change in voltage around any closed loop is zero.

Conclusion:

1. (a) The circuit can be reduced to a single resistor in series. Therefore, it is a single-loop circuit. Thus, option (a) is correct.
2. (b) Since option (a) is correct. Option (b) is incorrect.
3. (c) Knowing the resistance of $R_1$ and $R_2$ cannot be used to find the current using only Kirchhoff’s rules. Thus, option (c) is incorrect.
4. (d) Knowing the resistance of $R_1$ and $R_2$ can be used to find the current without using Kirchhoff’s rules. Thus, option (d) is correct.