How must a voltmeter be connected in a circuit?

[jimbo71]

Homework Statement

How must a voltmeter be connected in a circuit to measure voltage across a resistor and why?

Homework Equations

Vv=Ifs(Rc+Rs)

The Attempt at a Solution

I think the voltmeter must be connected parallel to the series with its terminals on either side of the resistor.

 

[LowlyPion]

... why?

 

[jimbo71]

I'm not sure