Question

Which of the following statements below are correct about the e.m.f of a cell:

• A. It is measured by the amount of work done per unit change in moving a positive test charge in the complete circuit inside and outside the cell.
• B. It depends on the amount of current drawn from the cell.
• C. It is measured by the amount of work done per unit charge in moving a positive test charge in the circuit outside the cell.
• D. It does not depend on the amount of current drawn from the cell.

Answer 1

Answer: (A), (D)

The correct options are
A It is measured by the amount of work done per unit change in moving a positive test charge in the complete circuit inside and outside the cell.
D It does not depend on the amount of current drawn from the cell.

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.)