Five identical incandescent lamps, each rated 100W at 200V, are connected in parallel to a 200V mains supply through a fuse that melts if the current exceeds 3A.
(i) Determine the resistance of a single lamp when it is operating at its rated values.
(ii) Calculate the equivalent resistance of the complete lamp circuit and the current drawn from the mains when all five lamps are glowing normally. State whether the fuse will remain intact.
(iii) One lamp filament burns out and becomes an open circuit, while the remaining four continue to operate. Recalculate the equivalent resistance of the circuit and the new current drawn from the mains. Comment on whether the fuse condition changes compared to part (ii).