Please explain the steps you take and why! Your neighbors have decorated the out
ID: 1716297 • Letter: P
Question
Please explain the steps you take and why!
Your neighbors have decorated the outside of their house with many strings of mini lights ("Christmas lights"). Within each 100-bulb string, the 100 lights are connected in series, but with one additional feature: when a bulb bums out, a "shunt" at the base of the bulb is designed to short-circuit. In this way, burning out one bulb turns a 100-bulb series arrangement into a 99-bulb series arrangement, instead of breaking the circuit and causing all 100 bulbs to go out. As a result, the string's net resistance decreases slightly. Your neighbors have put up 12 strings of 100 lights each, with strings connected end-to-end, and the first string plugged into a 120 V household outlet. As they put up the lights, you noticed that the first string burned equally brightly alone, as when the second string, or the 12th, was connected. Each bulb has a resistance of 5.1 Ohm. Are the strings connected to each other in series or in parallel? (Be sure to support with evidence/principles.) Draw a circuit diagram representing the arrangement. You can show just a few strings and just a few bulbs per string, as long as you represent clearly that your circuit repeats the few you've drawn. Represent the single voltage source as a battery. What is the outlet current for the 12-string arrangement? If the protection fuse built into the first string's plug can handle 3.0 amps without burning out, will this arrangement work? How much electrical power (in watts) does the 12-string arrangement consume? Eventually bulbs will begin to bum out. Will the 3-amp fuse blow sooner if the bumed-out bulbs are evenly distributed over the 12 strings, or if they are only in one string? What is the least number of bulbs that can bum out and cause the 3 A fuse to blow? Treat this as a DC (direct current) system, since we haven't yet discussed alternating current. For more details about how mini lights are wired, and how shunts work, see http://people.howstuffworks.com/culture-traditions/holidays/christmas-lightsl.htm.Explanation / Answer
(a)
all strings are connected in series with each other
(b)
Current I=120/5.1*100=0.235 for single string and 2.825 for 12 strings
(c)
w=120*0.235=28.02J
(d)
yes it is series connection, so it is equally distributed ti all bulbs and not works if single bulb is burned out