PhysicsLAB: Resistance, Wattage, and Brightness

Worksheet
Resistance, Wattage, and Brightness

Refer to the following information for the next seven questions.

Assume that all bulbs have filaments that are the same length.

1. Which statement is true of generic light bulbs that are rated at 40 watts and 75 watts when tested in 120-V outlets?

The 40 watt bulb has a thinner filament and therefore less resistance.
The 75 watt bulb has a thinner filament and therefore less resistance.
The 75 watt bulb has a thicker filament and therefore less resistance.
The 40 watt bulb has a thicker filament and therefore less resistance.

2. Two lamps, one with a thick filament and the other with a thin filament are connected in parallel. The current is greater in the lamp with the

thin filamentthick filamentthe same in each lamp

3. Two lamps, one with a thick filament and the other with a thin filament are connected in series to a battery. The voltage drop is greater in the lamp with the

thin filamentthick filamentthe same in each lamp

4. Two lamps, one with a thick filament and the other with a thin filament are connect in series. The current is greater in the lamp with the

thin filamentthick filamentthe same in each lamp

5. Two lamps, one with a thick filament and the other with a thin filament are connect in parallel across a battery. The voltage drop is greater in the lamp with the

thin filamentthick filamentthe same in each lamp

6. As more and more lamps are connected in a parallel circuit, the overall current drawn from the battery

decreasesremains the sameincreases

7. As more and more lamps are connected in a series circuit, the overall current drawn from the battery

decreasesremains the sameincreases

Refer to the following information for the next eleven questions.

In each of the following diagrams, all batteries have the same voltage and all lamps are identical.

8. Compared to A, lamp B would shine