ELECTRIC POTENTIAL AND POTENTIAL DIFFERENCE:-
-Potential difference: The difference between two points in an electric circuit carrying some current as the work done to move a unit charge from one point to the other – Potential difference (V) between two points = Work done (W)/Charge (Q)
The SI unit of electric potential difference is volt (V)
One volt is the potential difference between two points in a current carrying conductor when 1 joule of work is done to move a charge of 1 coulomb from one point to the other.
Therefore, 1 volt = 1 joule /1 coulomb
Voltmeter: The potential difference is measured by means of an instrument called the voltmeter. The voltmeter is always connected in parallel across the points between which the potential difference is to be measured.