(a) Different appliancies in a household electric circuit are connected in parallel so that :
(i) the appliancies work at the same voltage.
(ii) the appliancies can be operated independent of each other.
(b) Here `P = 1.5 kW = 1500 W, V = 220 V`
As `P = VI, I = (P)/(V) = (1500)/(220) = 6.81 A`
When `6.81 A` current flows through the fuse-wire of rating `5 A`, it melts and the circuit breaks. This is due to the reason that the current flowing through the fuse, i.e., `6.81 A` is more than its rating, i.e., `A`. In this case, a fuse of rating higher than `6.81 A` (i.e., say `10 A`) must be used.