JAMB - Physics (1988 - No. 31)
A household refrigerator is rated 200 watts. If electricity costs 5k per kWh, what is the cost of operating it in 20 days?
N4.80
N48.00
N480.00
N4800.00
解释
Energy(kWhr) = 200 x 10\(^{-3}\) x 20 x 24
= 96kwhr
1 kwhr cost 5 kobo; 96 kwhr will cost
5 x 96 = 480 kobo
= N4.80