Answer:
B. $5.18
Explanation:
Cost of electricity per kWh = $0.09
Power consumption of refrigerator = 320W = 320/1000 = 0.32kW
In a month (30 days) the refrigerator works 1/4 × 30 days = 7.5 days = 7.5 × 24 hours = 180 hours
Energy consumed in 180 hours = 0.32kW × 180h = 57.6kWh
Cost of electricity of 57.6kWh energy consumed by the refrigerator = 57.6 × $0.09 = $5.18
Answer:
B. $5.18
Explanation:
The power of refrigerator is given:
Power = P = 320 W = 0.320 KW
Since, the electricity cost of the month is required, therefore the no. of hours in a month have to be calculated. Therefore;
No. of hours in a month = (1 month)(30 days/month)(24 h / day)
No. of hours in a month = 720 hours
It is given that the refrigerator runs only one-quarter of the time, thus the time of electric consumption will be:
Time of electric consumption = (1/4)(No. of hours in a month)
Time of electric consumption = (1/4)(720 hours)
Time of electric consumption = 180 hours
Now, we will compute the electrical energy used, as follows:
Electric Energy Consumed = (Power)(Time of electric consumption)
Electric Energy Consumed = (0.32 KW)(180 h)
Electric Energy Consumed = 57.6 KWh
Finally, we calculate the electricity cost per month as follows:
Monthly Cost = (Unit Cost)(Electric Energy Consumed)
Monthly Cost = ($ 0.09/KWh)(57.6 KWh)
Monthly Cost = $5.18
