How would the reading of voltmeter (V) change if it is connected

Question

nincompoop · Answer

connected to what?

radar · Answer

Might read the voltage.  Assuming there is voltage at the point of connection, if it had been disconnected, then the change would be from 0 to the measured value.

parthkohli · Answer

If a voltmeter is connected between point A and B, the voltmeter's reading will be less than the actual potential difference between those two points.  This is because the resistance of the voltmeter will cause the effective resistance to be less than the resistance of the wire between A and B.