|
Power in DC circuits  using the Casio fx-83MS unless
otherwise stated
The maths in this topic is in relation to :-
P
= V x I, V = I x R, P = V2 / R, P = I2 x R
Here we have simple multiplication and division and
also raising to the power of two or squaring the number. The course will show
you each item. The button to be pressed will be shown but when numerals need
to be entered they will be shown as figures the screen result will be shown
at the end of in stages depending upon the calculation.
|
P
= V x I
|
What
is the power in watts with 10000V and 5 amps
|
|
|
 10000  5 
|
|
|
|
V
= I x R
|
What
is the voltage in V if 5 amps passes through a resistance of 18000
|
|
|
5 18000
|
|
Convert
90000V to kV
|
|
|
From
the above stage press  result 90kV
|
|
|
|
P
= V2 / R
|
Find
the power in watts with 125V and resistance 150
using the fx-83GT PLUS calculator
|
|
For
this calculation we need to introduce another key  try
the following :- 5 result 25.
So back to the question in hand :- Find the power
in watts with 125V and resistance 150
|
|
|
125   150 
|
|
|
From
the above stage press note the10 0
so the answer is indicating full value 104.1666667
W
but in the exam the figures would be near a whole
number !!!
|
|
|
|
P
= I2 x R
|
Find
the power in kilo watts with 12.5 Amps and resistance 150
|
|
|
12  5 150
|
|
Note
:-that the conversion to the "engineering" value has to be done
after the main calculation. The 03 indicates the kilo value 103
: Result 23.4375 kW
|
|
kilo 103
|
Mega 106
|
Giga 109
|
|
So that completes the calculations for this set.
There are more functions to show you but it is
hoped that you have taken all the above onboard and it is time to give
yourself a coffee / tea break !!!
Next Circuit theory
|
