A domestic lighting circuit has a fuse of 5 A. If the mains supply is at 230 V, calculate the maximum number of 36 W tube-lights that can be safely used in this circuit.


Let the maximum number of tube-lights be y.

Power of y tube-lights, P=36y


V=230V, I=5A


We know that


P = VI


36y = 230 x 5


36y = 1500


y=31.94


So, number of tube-lights required are 31.


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