
Capacitors in parallel have their values added together.
Example What is the total capacitance in microfarads for C_{1} =
3uF C_{2} = 5uF C_{3} = 10uF ? 

3
5
10
Result 18 

If you had been asked to give the answer in nano farads which is 1/1000
or 10^{3} smaller then you would press the
key until you see ^{03 } Result 18000 nanofarads 
You must know which exponential you are looking for with
the
key otherwise you can still end up with the wrong answer. 

This is the formulae for two capacitors in series.
Example What is the total capacitance in microfarads for C_{1} =
3uF C_{2} = 5uF ? 

3535 

If you had been asked to give the answer in nano farads which is 1/1000
or 10^{3} smaller then you would press
until you see ^{03 }and the Result 1875 nanofarads 

This is the formulae for more than two capacitors in series.
Example What is the total capacitance in nanofarads for C_{1} = 3uF
C_{2} = 5uF C_{3 }= 10 C_{4} = 28 ? 

1315110
128
Result 0.669uF when we round to 3 places of decimal. 

but this is
so one last function press
which give the reciprocal. 

then
for the final result, well nearly !!!! 

BUT you had been asked to give the answer in nano farads which is 1/1000
or 10^{3} smaller so you need to press
until you see ^{03 }and the Result 1494 nanofarads if we forget
the figures after the decimal point. In an exam it would be expected
that when asked for nanofarads then it wold be a whole number !! 
Again this example invokes the "Maths rule" with the division
being done first before the addition so no brackets are required.
In this last example the full screen of figures is shown as on the calculator
and has not been widened, as by now you should be familiar with what to expect
in the display. From now on we leave out the
button
as you know how to use it! 
T=CR 
T (in seconds) = C (in farads) x R ( in ohms)
Here as with ALL formula the value of the variables must be considered. It
is not often that you will use a capacitor as large as a Farad
the microfarad uF being more usual. 
Example . How long in seconds will it take for a
470uF capacitor to charge to 63% of the applied voltage V_{S }5V
through a resistor of
1k2 
In this example we are using the
In this example because we are using a "wrong" mix of numbers,
by that we have components which are not in the prefix correct for the equation
we will have to enter the number expressing them in terms of the prefix we
need.
To do this we need to introduce you to the exponential key . we know that
470uf can be written as 470 x 10^{6 }Farads and
120k can be written
as 120000 or 120 x
10^{3} so we
will be using this in the calculator input. So back to the question.
How long in seconds will it take for a 470uF capacitor to charge
to 63% of the applied voltage V_{S }5V through a resistor of
120k 

470
6
120
3
Result 56.4 seconds 
So by expressing the values given to those required by the
formula the answer comes out directly!! 
