A fuse wire rated for 5A will melt if 900J of energy is dissipated in it.
(i) A current of 8A is accidentally passed through the fuse. Calculate the power being dissipated in the fuse at that instant if its resistance is 0.20Ω.
(ii) Assuming the resistance remains constant until melting, determine the time for which this current must flow before the fuse melts.
(iii) If instead a current of 6A flows, will the fuse necessarily melt? Support your answer with suitable calculation.