Practical Voltage and Current Measurement

Purpose:  In this lab assignment, we will experimentally explore the behavior of non-ideal meters. The experiments in this assignment illustrate the effects of non-ideal voltage measurements.

Pre-lab:

Lab Procedures:
a) Construct the circuit of Figure 1. Measure the voltage Vout using your DMM. Using your pre-lab results, estimate the internal resistance of the voltmeter. b) Take a picture of your circuit and include it in your blog. 

The internal resistance of the DMM is about 10MΩ
c) Repeat the test of part (a), except use the voltmeter on your Analog Discovery module to measure Vout. Using your pre-lab results, estimate the internal resistance of the scope instrument. 

Conclusion:
In this experiment, we did not get the ideal result for the voltage across each resistor as 2.5V when we use 10MΩ for both resistors. The reason is the internal resistance in DMM also 10MΩ that means the resistor and the internal resistor of DMM are connected in series which make the voltage across was 1.66V. It is the same when using the voltmeter on Analog Discovery but its resistance was very small compares to the internal resistance of DMM.