Consider the problem of using a low-voltage system to power a small cabin. Suppose a 12-V system powers a pair of 100-W lightbulbs (wired in parallel).
a. What would be the (filament) resistance of a bulb designed to use 100 W when it receives 12 V?
b. What would be the current drawn by two such bulbs if each receives a full 12 V?
c. What gage wire should be used if it is the minimum size that will carry the current.
d. Suppose a 12-V battery located 80-ft away supplies current to the pair of bulbs through the wire you picked in (c). Find:
1. The equivalent resistance of the two bulbs plus the wire resistance to and from the battery.
2. Current delivered by the battery
3. The actual voltage across the bulbs
4. The power lost in the wires
5. The power delivered to the bulbs
6. The fraction of the power delivered by the battery that is lost in the wires.