# Works done equals to $f×s$. Now, when the test charge is taken around the circuit, the displacement is zero. Then the EMF of the cell should be equals to zero!!??     The e.m.f. of a cell is defined as the energy spent (or the work done) per unit charge in taking a positive test charge around the complete circuit of the cell (i.e., in the circuit outside the cell as well as in the electrolyte inside the cell).

Dear student,
Here, in this case, the formula for calculating work comes with a function of charge and the distance, about which you will study in your higher grades, this is why the simple concept of displacement is not applicable here.
Regards

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