PASCO EM-8656 AC_DC ELECTRONICS LABORATORY - Manual (Page 13)

9
012-05892A AC/DC Electronics Laboratory
®
EQUIPMENT NEEDED:
– AC/DC Electronics Lab Board: Wire Leads
– D-cell Battery
– Multimeter
– Graph Paper
Purpose
The purpose of this lab will be to investigate the three variables involved in a mathematical
relationship known as Ohm’s Law.
Procedure
➀
Choose one of the resistors that you have been given. Using the chart on the next page, decode
the resistance value and record that value in the first column of Table 3.1.
➁
MEASURING CURRENT: Construct the circuit shown in Figure 3.1a by pressing the
leads of the resistor into two of the springs in the Experimental Section on the Circuits
Experiment Board.
➂
Set the Multimeter to the 200 mA range, noting any special connections needed for measuring
current. Connect the circuit and read the current that is flowing through the resistor. Record this
value in the second column of Table 3.1.
➃ Remove the resistor and choose another. Record its resistance value in Table 3.1 then measure
and record the current as in steps 2 and 3. Continue this process until you have completed all of
the resistors you have been given. As you have more than one resistor with the same value, keep
them in order as you will use them again in the next steps.
➄ MEASURING VOLTAGE: Disconnect the Multimeter and connect a wire from the positive
lead (spring) of the battery directly to the first resistor you used as shown in Figure 3.1b. Change
the Multimeter to the 2 VDC scale and connect the leads as shown also in Figure 3.1b. Measure
the voltage across the resistor and record it in Table 3.1.
➅ Remove the resistor and choose the next one you used. Record its voltage in Table 3.1 as in step
5. Continue this process until you have completed all of the resistors.
Experiment 3: Ohm’s Law
–
+
Red (+)
Black (-)
Battery –
+
Red (+)
Black (-)
Battery
Figure 3.1a Figure 3.1b