home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
HAM Radio 1
/
HamRadio.cdr
/
misc
/
eleclern
/
3.chn
(
.txt
)
< prev
next >
Wrap
Turbo Pascal Chain module
|
1985-07-29
|
13KB
|
182 lines
To continue, press any key
G (*=======================================================*)
G (* *)
G (* Elementary Electricity *)
G (* *)
G (* Tutorial No. 3 *)
G (* *)
G (* PARALLEL RESISTORS *)
G (* *)
G (* Version 1.0 *)
G (* *)
G (* This program will show you how to calculate the *)
G (* resistance of any number of resistors connected *)
G (* in parallel. *)
G (* *)
G (* You will be required to make some simple calcu- *)
G (* lations and enter your results into the computer. *)
G (* *)
G (* Written by T. J. Meyers April 6, 1985 *(
G (* *(
G (*=======================================================*)
: PARALLEL RESISTORS
:The following sketch illustrates how two resistors may be
:connected in parallel. Assume the electrical current to
;flow INTO the left end and OUT of the right. Note that when
:the charges reach the first juncture they have the choice
:of flowing through either resistance. The amount of flow
:through a given resistance will be in inverse proportion
:to its value. More charges will flow through the smaller
:of the two resistances. Of course, if both resistances
:have the save value, the current will be the same in each.
: R-1
:
: ..../\ /\ /\ /\ /\.....
: - > .........: \/ \/ \/ \/ :........> +
: : :
: :.../\ /\ /\ /\ /\....:
: \/ \/ \/ \/
: R-2
: PARALLEL RESISTORS
;The figure below shows two RESISTORS connected in parallel.
9 +-----[0000000000]-----+
9 <--------I I-------->
9 +-----[0000000000]-----+
<The EQUATION required to calculate the equivalent resistance
6of two or more resistors connected in parallel is:
3 1/R(t) = l/r(1) + l/r(2) + ......1/r(n)
<A little work with simple algebra will show you that for two
=resistors the preceding equation may be rewritten for ease of
calculation as follows:
+ R(t) = r(1) * r(2) / (r(1) + r(2))
+ THREE RESISTORS IN PARALLEL
:Using the equation for 2 resistors in parallel as a guide,
/write the equation for 3 resistors in parallel.
6First, on a piece of paper, write the equation in the
6reciprocal form. Then, using the necessary algebra,
6rewrite it, solving for R. Enter this second version
into the computer.
*DO NOT SKIP ANY SPACES BETWEEN CHARACTERS.
>Just in case you have forgotten, here are the two forms of the
equation for 2 resistors.
> 1/R(t)=1/r(1)+1/r(2) and R(t)=r(1)*r(2)/(r(1)+r(2))
;The equation for three resistors connected in parallel is:
3R(t)=r(1)*r(2)*r(3)/(r(1)*r(2)+r(2)*r(3)+r(1)*r(3))
#Very good! You have earned a star.
Sorry - please try again.
1The equation for 3 resistors in parallel is:
3R(t)=r(1)*r(2)*r(3)/(r(1)*r(2)+r(2)*r(3)+r(1)*r(3))
Good! You get a star.
?Too bad - wrong again. The correct equation for 3 resistors is:
3R(t)=r(1)*r(2)*r(3)/(r(1)*r(2)+r(2)*r(3)+r(1)*r(3))
Better luck next time.
1 CALCULATIONS
4The opposition to the flow of electric current in an
4electrical conductor is called RESISTANCE. The unit
4of electric resistance is the OHM. The ohm is named
4in honor of Georg Ohm, a German physicist, who did
%research in the field of electricity.
/So much for background. Now for some problems.
6Using the appropriate equation, calculate the answers
6to the following items on a piece of paper and enter
your results into the computer.
2No. R(1) R(2) R(t)
2 ohms ohms ohms
1
?
2
?
3
?
*The answer to No. 1 is:
Correct. Paste up a star.
You just made a boo-boo.
$The correct answer is:
*The answer to No. 2 is:
Right. You may add a star.
A swing and a miss!
$The correct answer is:
*The answer to No. 3 is:
On target! Take a star.
(We all have our bad days. Not to worry.
$The correct answer is:
8By now the data should have displayed a pattern. It is:
9 When two resistors of the same value are connected
4 in parallel, the equivalent resistance is just
% ONE-HALf of ONE resistor alone.
4 PROBLEMS
=You will now be asked to solve a series of 5 problems. The
=problems will involve 2, 3, and 4 resistors connected in
parallel.
<In addition to paper and pencil, a calculator would make the
task easier.
9Determine each answer to 3 decimal places, then round off
:to 2 decimal places. Finally, enter your answer into the
computer.
If R(1) =
ohms and R(2) =
ohms, R(t) =
A good beginning and a star.
An error. The correct answer is
ohms. Perhaps
4you might like to check your work before going on to
the next problem.
If R(1) =
ohms and R(2) =
ohms, R(t) =
A correct answer and a star.
)A miscalculation. The correct answer is
ohms.
5Find the error before proceeding to the next problem.
If R(1) =
ohms and R(2) =
ohms, R(t) =
Very good considering that this problem did not
&come out even. Give yourself 2 stars!
Incorrect. The right answer is
ohms, rounded.
4This one was a little tougher than the previous two.
0Be sure to find your mistake before you proceed.
If R(1) =
ohms, R(2) =
ohms, and
R(3) =
ohms,
7 then R(t) =
8Excellent! You appear to have a good grasp of resistors
)connected in parallel. Take three stars.
<You do seem to have a bit of trouble. The correct answer is
3 ohms. Check your work carefully before continuing.
<This is the 5th and final problem. It involves 4 resistors.
If R(1) =
ohms, R(2) =
ohms
R(3) =
ohms, R(4) =
ohms
7 then R(t) =
4Super! Take four stars. You have just demonstrated
<an excellent understanding of the consequences of connecting
+a multiple number of resistors in parallel.
2Sorry, you must try again. The correct answer is
ohms, rounded.
<Carefully check to see whether you have written the equation
;correctly. Then make sure that you have entered the proper
1values. Lastly, review all of your calculations.
/If you still have a problem, have someone check
your work for you. Good luck.
" SUMMARY
@If you have successfully solved all of these problems you should
-have noticed a new pattern emerging. It is:
AConnecting two or more resistors in parallel always results in an
Aequivalent resistance which is smaller in value than the smaller,
+or smallest, of the resistors so connected.
9 Press spacebar to try again
9 To return to the menu
9 first, type (q,Q) to quit,
9 then, type (menu,MENU) at A>
; Press (q/Q) to quit