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CBSE Class 12-science Answered

Can we use a voltmeter to measure emf of the cell.Justify ur answer
Asked by Moksha | 21 Aug, 2011, 12:00: AM
answered-by-expert Expert Answer

The electromotive force (emf) of a cell is its terminal voltage when no current is flowing through it. The terminal voltage of a cell is the potential difference between its electrodes. A voltmeter cannot be used to measure the emf of a cell because a voltmeter draws some current from the cell. To measure a cell's emf a potentiometer is used since in a potentiometer measurement no current is flowing. It employs a null method of measuring potential difference, so that when a balance is reached and the reading is being taken, no current is drawn from the source to be measured.

 

Answered by | 22 Aug, 2011, 05:06: PM

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CBSE 12-science - Physics
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