In the diagram above, a bulb is lit by drawing 2.0A from 440V a.c. source. Calculate the cost of keeping the bulb on for two days at $0.40 per kilowatt-hour.
Attached Figure / Diagram
A
$16.90
B
$84.48
C
$1690.00
D
$8.48
Verified Correct Answer: A.
Physical Principles & Numerical Solution
Power[p] = IV → 2 * 440 = 880Watt
Energy = p * t = 880 * 48hrs
= 42240 or 42.24kwh
But 1 kwh cost $0.40
∴ 42.24kwh costs 42.24 x 0.40
= 16.896 or $16.90
Source: WAEC / JAMB / NECO Classroom Archive (Record #61984)