A 2 kW electric fire is switched on for 30 minutes. How many Units of electricity does it use?

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Units of electricity are measured in kWh (kilowatt-hours).

We have our power in kW  (2 kW)

We have our time in minutes  (30 minutes)

Looking at the units, we can see that:

kW x minutes   =  kWminutes   (kWm)

and

kW x hours   =   kWhours         (kWh)

 

So, to get our answer in kWh, we must first convert our time to hours:

30 minutes = 0.5 hours

 

then

2 kW  x  0.5 hours  =  1 kWh

 

So our answer is 1 kWh.

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