Find the cost of operating an electric appliance for 10 hours at 30 kobo per kwh, if it takes \(3 \mathrm{~A}\) when connected to a \(220 \mathrm{~V}\) supply.
A. N66 B. \(\# 1.32\) C. #1.98 D. N2.62
Correct Answer: C
Explanation
\(\mathrm{P}=\mathrm{IV}=(3 \times 220) \mathrm{W}=660 \mathrm{~W}=0.66 \mathrm{KW}\), \(\mathrm{t}=10 \mathrm{hrs}\)nergy \(=\) power \(\times\) time \(=0.66 \mathrm{KW} \times 10 \mathrm{~h}\) \(=6.6 \mathrm{KWh}\) Since \(1 \mathrm{KWh}\) cost \(30 \mathrm{kobo}\), the cost of \(6.6 \mathrm{KWh}\) \(=(30 \times 6.6) \mathrm{K}=198 \mathrm{~K}=\mathrm{N} 1.98\)
