Chapter 18 Direct-Current Circuits Quick Quizzes 1.(a), (d). Bulb R1becomes brighter. Connecting a wire from bto cprovides a nearly zero resistance path from bto cand decreases the total resistance of the circuit from R1+ R2to just R1. Ignoring internal resistance, the potential difference maintained by the battery is unchanged while the resistance of the circuit has decreased. The current passing through bulb R1increases, causing this bulb to glow brighter. Bulb R2goes out because essentially all of the current now passes through the wire connecting band cand bypasses the filament of Bulb R2. 2.(b). When the switch is opened, resistors R1and R2 are in series, so that the total circuit resistance is larger than when the switch was closed. As a result, the current decreases. 3.(a). When the switch is closed, resistors R1and R2are in parallel, so that the total circuit resistance is smaller than when the switch was open. As a result, the total current increases.
This is the end of the preview.
access the rest of the document.