Chapter 21, Problem 84GP

CE Predict/Explain (a) Referring to Problem 83 and the circuit in Figure 21-56, does the current supplied by the battery increase, decrease, or remain the same when the switch is closed? (b) Choose the best explanation from among the following:

1. I.                    The current decreases because only two resistors can draw current from the battery when the switch is closed.
2. II.                  Closing the switch makes no difference to the current since the second resistor is still connected to the battery as before.
3. III.               Closing the switch shorts out the second resistor, decreases the total resistance of the circuit, and increases the current.

Figure 21-56