Two light bulbs have resistances of 400 ω and 800 ωthe two light bulbs are connected in series across a 120- v line. find the current through each bulb. enter your answers numerically separated by a comma. i 400, i 800 = bfind the power dissipated in each bulb. p 400, p 800 = cfind the total power dissipated in both bulbs. p =

1) Current in each bulb: 0.1 A

The two light bulbs are connected in series, this means that their equivalent resistance is just the sum of the two resistances:

And so, the current through the circuit is (using Ohm's law):

And since the two bulbs are connected in series, the current through each bulb is the same.

2) 4 W and 8 W

The power dissipated by each bulb is given by the formula:

where I is the current and R is the resistance.

For the first bulb:

For the second bulb:

3) 12 W

The total power dissipated in both bulbs is simply the sum of the power dissipated by each bulb, so: