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
We know that
P = VI
36y = 230 x 5
36y = 1500
So, number of tube-lights required are 31.