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:

$x=\frac{10\min\cdot1h}{60\min}\Rightarrow x=\frac{1}{6}h$

Then:

$\frac{240.0W}{(1/6h)}=1440\cdot\frac{W}{h}\cdot\frac{kW}{1000W}=1.44kW/h$

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:

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