Lab 14B Power

Then, repeat with two bulbs. Set up the basic circuit above and record the voltage, current, and power supplied to the bulb. Then, repeat with two bulbs.

Charging the capacitor: Use the FOUR battery box and measure the voltage of four batteries. Using alligator clips, hook the + end of the battery box to the + terminal on the capacitor. Use the tall, blue capacitors. Hook the negative terminals up the same way. After a few seconds, disconnect the clips and measure the voltage across the capacitor. Make sure the capacitor is holding the full voltage of the four batteries. Use the battery box to power a single bulb so that you can get a current measurement. Write it down.

Using your previous circuit, AND KEEPING THE SWITCH OPEN, hook up the capacitor in place of the battery. Time how long the capacitor can keep the bulb lit once the switch is closed. Record three trials and take the average time.

Answer the following questions: What was the average time the capacitor provided power? What was the power (watts) provided by the capacitor? How much energy (E = Pt) did it supply? (energy is in joules, remember!) Would a decent capacitor (not these) be able to light 3 bulbs in series or 3 bulbs in parallel longer? Why?

Capacitors powering series vs. parallel Repeat this experiment to determine the average time for the capacitor to power 3 bulbs in series vs 3 bulbs in parallel. Then, hook up the smaller, blue capacitor and repeat the above experiment to determine the difference (if any) between times. Look at the capacitance for both blue capacitors. Use those values to explain the difference in times.