Page locked

This page is currently locked for editing by another user. You have to wait until this user finishes editing or the lock expires.

Currently locked by: 192.168.48.6,216.73.216.142
Lock expires at: 2026/03/19 05:55 (15 min)

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.

==== Resistance measurement ====
 
Procedure for resistance measurement:
  * Set the measuring device to resistance measurement 
  * Connect the resistance to be measured to the corresponding sockets on the measuring device (the measuring device sockets labeled COM and $\Omega$
  * Read the measured value 

There are different types of resistance measurement: 
  * **direct** resistance measurement 
  * **indirect** resistance measurement

\\
=== Direct resistance measurement ===
\\
Determine the nominal and measured values of the resistance for $R_{~\rm 1}$ (brown, green, orange), $R_{~\rm 2}$ (yellow, violet, red), $R_{~\rm 3}$ (red, violet, red) and the incandescent lamp $R_{~\rm L}$. Also measure the approximate resistance $R_{~\rm K}$ of your body from your right to your left hand.

{{drawio>Table-1_V2.png}}
<tabcaption Table-1_V2 | Direct resistance measurement> </tabcaption>    
\\ 

How do you explain the deviation between $R_{~\rm L,nominal}$ and $R_{~\rm L,meas}$?
<wrap onlyprint> \\ \\ \\ \\  </wrap>\\
\\
\\
What consequences can $R_{~\rm K}$ have?
<wrap onlyprint> \\ \\ \\ \\  </wrap>\\
\\
\\
Now determine the series and parallel connections of resistors $R_{~\rm 1}$, $R_{~\rm 2}$ and $R_{~\rm 3}$. \\
Specify the formulas used: \\

$R_{~\rm serial}$ =  \\
<wrap onlyprint> \\ \\  </wrap> \\
$R_{~\rm parallel}$ (= $R_{~\rm a}$ || $R_{~\rm b}$) =
<wrap onlyprint> \\ \\  </wrap> \\

{{drawio>Table-2_V1-Serial+parallel.png}}
<tabcaption Table-2_V1 | Series and parallel connections> </tabcaption> 
\\
\\
=== Indirect resistance measurement ===
\\
The resistances can also be determined by measuring the current/voltage.

**Ohm's law: In an electrical circuit, the current increases with increasing voltage and decreases with increasing resistance.** \\ 
$$ I=\frac{U}{R} $$

Build the measuring circuit shown in <imgref Fig-1_V1> for each of the three resistors and set the voltage on the power supply to $~{\rm 12} ~{ V}$.

{{drawio>Fig-1_V1-indirect-measurement.png}}
<imgcaption Fig-1_V1 | Indirect resistance measurement> </imgcaption>

Measure $U_{~\rm n}$ [V] and $I_{~\rm n}$ [mA]. Calculate $R_{~\rm n}$ [k$\Omega$] from these values.

{{drawio>Table-3_V1-indirect-measurement.png}}
<tabcaption Table-3_V1 | Indirect resistance measurement> </tabcaption>