Question

Estimate the monthly cost of using a 700-W refrigerator that runs for 10 h a day if the cost per kWh is $0.20.

Answer 1

Power consumed by the refrigerator is given as

$P = 700 W$

Now if refrigerator is used 10 h a day then total usage of refrigerator for 1 month will be given as

$t = 10 * 30 = 300 h$

now the total energy consumed in one month is given as

$E = P * t$

$E = 700 * 300$

$E = 210000$

$E = 210 kWh$

now it is given that cost of one kWh is $0.20

then total cost of one month is given as

$C = 0.20 * 210$

$C = 42$