Question

A house hold circuit has a fuse of 5 A rating. Calculate the maximum number of bulbs of rating 60 W - 220 V each which can be connected in this house hold circuit.

Answer 1

Current drawn by one bulb,
`I= P/V = 60/220 = 3/11 A`
No. of bulbs which can be safely used with 5 A fuse = `5/(3//11) = 55/3 = 18.33`.
Thus, 18 bulbs can be used safely with 5 A fuse.