Theory Question (Kirchhoff's Law)

[Bob_Builder]

Homework Statement

To ensure the source's in the circuit are supplying the correct voltage for the experiment, we measured the terminal voltage. Why do we have to measure terminal voltage after the connection is made

Homework Equations

The Attempt at a Solution

if we check the terminal voltage and its right than we are ensuring that all our measurements will have little or no error?

 

[willem2]

suppose the terminal voltage would be much lower than the rating of the source.
what could be the cause of that?