Electric choke

I do get the importance of checking for voltage loss/drop and it is a must do.
But are we talking using a volt meter or Ohm meter? Because using a voltage meter wouldn't you have to have one probe on the negative in order for it to read anything when probing a positive? I mean checking a battery you put one on positive and the other on the negative..Right? If you put them both on the positive you'll get nuttin..unless there is something I haven't learned yet .

My .02...Pete