JAMB - Physics (2011 - No. 31)
If the charge of electricity is K wh is N4, what is the cost of operating an electrical appliance rated 250 v,2 A for six hours?
N28
N12
N16
N24
Uitleg
Energy consumed = power x time = lvt = 2 x 250 x 6hr = 300 wh = 3 kwh but 1 kwh = N4
3 kwh = 3 x N4 = N 12
3 kwh = 3 x N4 = N 12