Question

How much does it cost to run a refrigerator for one day, if it turns on for 10 minutes each hour to draw 2.0 A from a 120 V source?

Answer 1

We will have the following:

First, we will calculate the consumption in the timelapse given:

`P=(2.0A)(120V)\Rightarrow P=240.0W`

Now we determine the fraction of one hour that 10 minutes represent:

`x=(10\min\cdot1h)/(60\min)\Rightarrow x=(1)/(6)h`

Then:

`(240.0W)/((1/6h))=1440\cdot(W)/(h)\cdot(kW)/(1000W)=1.44kW/h`

So:

`24\cdot1.44kW/h=34.56\text{kWh}`

Then we will have that it will consume 34.56 Kwh each day, the cost of consumption will be given by:

`\text{Cost of consumption=34.56kW/h }\cdot\text{ Cost of each Kw/h}`