Electromotive force (EMF) of the cell

Electromotive force (EMF) of the cell.

In this topic we will discuss about what is Electromotive force (EMF) of the cell and it is different from potential difference .

As we know electric current flows through a complete closed circuit ,when there is an source of external force which can bring the ions from low potential to high potential . This external for which makes the current carriers to move in a definite direction called electromotive force (EMF) . In another words we can define ‘ It is the maximum potential difference between two electrodes of the cell when no current flows through the circuits i.e. in open (off) circuit‘ .

Unit of the EMF is Volt (V) and it is generally represented by ‘E’

Difference between EMF of a cell and potential difference –

(i)  EMF -It is related with source of current

P.D. – It is related with any two points of the closed circuit.

(ii)  EMF – It cause of potential difference between two point of circuit .

P.D. – It is an effect .

(III)  EMF – It is the amount of work done in taking a unit charge once round the complete circuit .

P.D. – It is the amount of work done to bring unit charge from one point to another point .

(iv)  EMF – It is equal to sum of potential difference across all components of the circuit ( Including all          the cells connected  in the circuit .

P.D. – In a closed circuit the different components of the circuit have different potential difference .

(v)   EMF – It is independent of the external resistance and current drawn from the circuit .

P.D. – It depends on the resistance between two points of circuit and current flowing through it .

To know about what is  electric current ? click here-

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