Texas Instruments TI-86 - Manual (Page 260)

248
Chapter 19: Applications
19APPS.DOC TI-86, Chap 19, US English Bob Fedorisko Revised: 02/13/01 2:41 PM Printed: 02/13/01 3:05 PM Page 248 of 18 19APPS.DOC TI-86, Chap 19, US English Bob Fedorisko Revised: 02/13/01 2:41 PM Printed: 02/13/01 3:05 PM Page 248 of 18
Electrical Circuits
A measurement device has measured the DC current (C) in milliamperes and voltage (V) in
volts on an unknown circuit. From these measurements, you can calculate power (P) in
milliwatts using the equation
CV=P . What is the average of the measured power?
With the TI -86, you can estimate the power in milliwatts at a current of 125 milliamperes
using the trace cursor, the interpolate àextrapolate editor, and a regression forecast.
ᕡ In two consecutive columns of the list editor, store the current
measurements shown below to the list name CURR and the
voltage measurements shown below to the list name VOLT .
{10,20,40,60,80,100,120,140,160}¶CURR
{2,4.2,10,18,32.8,56,73.2,98,136}¶VOLT
ᕢ In the next column of the list editor, enter the list name POWER .
ᕣ Enter the formula CURR ¹ VOLT in the list editor entry line for
POWER . Press b to calculate the values for power and store
the answers to the list name POWER .
ᕤ Select WIND from the GRAPH menu and set the window variable values as shown.
xMin=0 xMax=max(POWER) xScl=1000 yMin= 0 yMax=max(CURR) yScl=10 xRes=4
ᕥ From the home screen, select FnOff from the CATALOG and
press b to deselect all functions in the equation editor.
Select
Plot1( from the CATALOG and set up a stat plot with
POWER on the x-axis and CURR on the y-axis.