posted by k .
Light bulb packages will have at least two numbers on them; a power and what the potential difference across the bulb must be so that the bulb has the listed power. You go to the store and purchase two light bulbs. The package for Bulb A says 40 W in a large font with 120 V in a smaller font; the package for Bulb B says 60 W in a large font with 120 V in a smaller font. You then connect the light bulbs as shown below (where the emf is 120 V):