What is the unit in which e.m.f is measured ?

Hint: E.M.F stands for electromotive force. Electromotive force is the electrical action produced by a non-electrical source. Electrical devices provide an e.m.f by converting other forms of energy into electrical energy.

Complete answer:
Firstly, we need to understand the concept of potential difference.Potential difference is the difference of electric potentials between any two points in a closed circuit. And It’s measured in work done per unit positive charge and Its SI unit is Volts denoted as $V$.

Now, Electromotive force (EMF) is the maximum potential difference between the two electrodes of the cell when no current is drawn from the cell and the circuit is open. EMF is independent of the resistance of the circuit. EMF is greater than the potential difference between any two points in a circuit.

It’s to remember that EMF is not a particular force as the name suggests but a measurement of potential difference and It's measured in Volts denoted as $V$. which is equivalent to the meter-kilogram-second.
$\text{EMF}= \dfrac{\text{Joules}}{\text{Coulombs}}$
The symbol for EMF is $E$ and its general formula is given as,
$E = V + Ir$
Where the $V$ voltage of the cell is, $I$ is current across the circuit and $r$ is the internal resistance of the cell.

Note: Electromotive force remains constant but potential difference may varies and EMF can also be positive as well as negative and the dimensional formula of electromotive force may be represented as ${M^1}{L^2}{T^{ - 3}}{I^{ - 1}}$, $M$ is mass $L$ is length $T$ is time and $I$ is current.