Two 110-V light bulbs, one labeled 25 W and the other 100 W, are connected in series to a 110 V source.Then:
A)the current in the 100-W bulb is greater than that in the 25-W bulb
B)the current in the 100-W bulb is less than that in the 25-W bulb
C)both bulbs will light with equal brightness
D)each bulb will have a potential difference of 55 V
E)none of the above

Question

Quizplus · Accepted Answer

When two bulbs are connected in series, the same current flows through both, regardless of their wattage ratings. The brightness of each bulb and the potential difference across each will depend on their resistance, which is not directly given by the wattage when connected in series to a different voltage than they are rated for. The 25-W bulb, having higher resistance, will drop more voltage than the 100-W bulb, making options A, B, C, and D incorrect without further information.

Two 110-V Light Bulbs, One Labeled 25 W and the Other