Determine the current passing through each of the bulbs

Question

In old fashion string of 80 Christmas lights is wired in series. Each bulb has a resistance of 2.0 ohms and the entire string is plugged into a 120 V outlet

Answer 1

Resistances wired in series are additive, therefore the whole circuit has

resistance of R = 80×2Ω = 160Ω.

The current is determined from Ohm's Law:

I = U/R = 120V/160Ω = 0.75A