These are the reasons why new Christmas light strands are wired in parallel. Parallel wiring allows
for several paths that electricity can take to get from the energy source to where the power is
grounded. Even with several strings of lights connected, each string functions in parallel, not in a
series. If one bulb burns out, the rest will keep functioning. This makes it simple to pinpoint the
problem bulb and replace it. On strings where the bulbs are permanent, the rest of the string can
still function (always consult the manufacturer’s instructions on how to deal with burned-out
bulbs).
The other feature that makes parallel wiring preferable for Christmas lights is that adding strings
will not impact the brilliance of the lights on a whole. The amount of power flowing to each bulb
remains constant.
The only consideration that will determine whether or not all the lights stay lit is where they are
plugged in. If they are plugged into a circuit that is not already under heavy load, it would take a
large number of lights to trip the circuit – more than most people will ever use at one time.
Q5. If you remove a bulb in your parallel circuit, with the other bulb(s) still light? Explain why?
Nothing happens to the other light bulbs in a parallel circuit when the middle bulb is removed
because the other light bulbs still have a connection to the voltage source.