Ok, Emf is the voltage in a cell when no current flows through the circuit.
Then how do we measure it?
If one says that connect the cell (of unknown emf) having some finite internal resistance with the voltmeter(assume it is ideal) in parallel and u will get the emf of the cell.
Now my question is if I do this, this means that the cell is sending some current through the circuit which further means that I have calculated the terminal voltage(voltage across the terminals of the cell which sends the current in circuit).
And we know that when a cell discharges emf is greater than the Terminal Voltage
So how to measure the emf of a cell(if I am not wrong till here)???