# In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of electric mains is 220 V. The mi

30 views
in Physics
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of electric mains is 220 V. The minimum capacity fo the main fuse of the building will be :
A. 8 A
B. 10 A
C. 12 A
D. 14 A

by (73.0k points)
Correct Answer - C
by (50.0k points)

Total power of all the devices

$=[15\times40+5\times100+5\times80+1\times1000]W=2500 W$

$\therefore$ Current $=\frac{2500 W}{220 V}=11.36 A \approx12A.$

$\therefore$ Minimum capacity of the main fuse should be 12 A.