Final answer:
To find the total power dissipation of two light bulbs in parallel, sum their individual power ratings; a 60-W and 25-W bulb connected in parallel to a 120-V line will dissipate a total of 85 W.
Step-by-step explanation:
To calculate the total power dissipation of two light bulbs connected in parallel across a 120-V line, we need to consider each bulb individually. For instance, a 60-W light bulb and a 25-W light bulb will both operate at 120 V in a parallel circuit. The power dissipated by each bulb is equal to the power rating, assuming they are designed to operate at 120 V. Therefore, the 60-W bulb will dissipate 60 W and the 25-W bulb will dissipate 25 W.
In a parallel circuit, the power dissipated by the bulbs simply adds up, because each bulb has the full voltage across it and they do not affect each other's operation. So the total power dissipated in the circuit with both bulbs will be the sum of the individual powers: 60 W + 25 W = 85 W.