Question

Three appliances are connected in parallel to the same source which provides a voltage of 220 V. A fuse connected to the source will blow if the current from the source exceeds 10 A. If the three appliances are rated at 60 W, 500 W and 1200 W at 220 V, will the fuse blow?

Answer 1

Voltage of power supply, V = 220 V
Power rating of the first appliance = 60 W
So, current drawn by the first appliance = 60 / 220 = 0.27 A
Power rating of the second appliance = 500 W
So, current drawn by the second appliance = 500 / 220 = 2.27 A
Power rating of the first appliance = 1200 W
So, current drawn by the first appliance = 1200 / 220 = 5.45 A
Net current drawn by all the appliances = 0.27 + 2.27 + 5.45
= 5.99 A
It is given that the rating of the fuse is 10 A. It will not blow when all the appliances are used together because current capacity of the fuse is more than the value of current drawn by the device.