I NEED HELP PLEASE, THANKS! :) Holiday lights are often connected in series and use special lamps that short out when the potential difference across a lamp increases to the line voltage. Generate an explanation why and explain why these light sets might blow their fuses after many bulbs have failed.

if there isn't a shorting mechanism, the whole sets will be blown out several lamps and then shortened, the overall resistance of the remaining operating lamps will be decreased resulting in an increased working current that is adequate to blast the fuse

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27