Calculating Bills
To calculate your monthly bill you must
use the power equation and readjust it accordingly.
Power
equations:
P=I*V
p=(V^2)/R
p=(I^2)*R
P= Power dissipated which is measured in (Watts)
I= Current which is measured in (Amps)
R= Resistance which is measured in Ohms (The Unique
symbol for Ohms Ω )
Example Of Monthly Bill Calculations For One Device
A small refrigerator has a Resistor reading of 102
(Ω) and current of 1.3 amps and the local area charges
.1543(cents/Kw Hr) used per month.
Using the power equation we use P=(I^2)*R then we input the
numbers as shown P= (1.3^2)*102. The
power of the refrigerator now reads 172.38 watts, which you
have to convert into kilowatts to match the rates of the
billing price. When converting watts to kilowatts you divided
by 1000. Then the new power value is .17238 kilowatts. You
will then have to take this value and multiply it by the
number of hours in a day, which is 24. So 24 hrs *.17238
kilowatt is equal to 4.137 kilowatt*hrs. This number tells you
the amount of power the refrigerator dissipates in one day. To
know your bill for that single day you multiply your power
dissipated by the refrigerator by the rate that the local area
charges. This values comes out to be $ .64 per day.
To figure out the monthly charge, you take the charge per day
of the refrigerator and multiply it by 30 days. You will then
find that the refrigerator costs $19.15 per month.
Straight Forward Calculations
After plugging in known values into the power
equations (P=(I^2)*R):
P= (1.3^2)*120
Calculations:
P=172.38 watts
Want to convert in kw so divide by 1000:
P= .17238 kw
Then multiply your power dissipation by the number of hours in
one day which is 24:
P= 4.1371kw*hr
With the power dissipation in 1 day you can find the charge in
1 day by multiplying it with the rate of the charge per kw*hr
(The rate is $.1543 per kw*hr ):
$.64 per day
To find Monthly Bill you multiply it by 30 days.
$19.15 per month