Emf Of A Cell - Practice Questions & MCQ

Cell

The device which converts Chemical energy into electrical energy is known as an electric cell.

• It maintains the flow of charge inside the circuit by supplying energy.

•  The direction of flow of current:

1.  inside the cell is from negative to positive electrode

2.  while outside the cell is from positive to negative electrode.

•  Electromotive force (Emf) of a cell: 

 It is the work done / energy carried by unit charge passing through one complete cycle of the circuit.

E=W/q

unit of emf is volt.

 The emf of cell is also known as potential difference across the terminals of a cell when it is not giving any current.

 Note-Cell is a source of constant emf but not constant current.

 Potential difference (V)- It is the work done / energy carried by unit charge passing through external part (excluding the cell ) of the circuit.

Potential difference is equal to the product of current and resistance of that given part.

i.e. $V_{A B}=i R$.