Question

how to solve the numericals related to the potentiometer

Answer 1

1.Cell A device to maintain a steady current in an electric circuit is electrolytic cell. It has two electrodes positive (F) and negative (N) as shown in figure below.

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2.Internal Resistance The electrolyte through which a current flows has a finite resistance r, called the internal resistance.

3.The emf of cell is the potential difference between two terminals of cell when there is no flow of current through it.

The potential difference between two terminals of cell when current flows through it, is known as terminal voltage or terminal potential difference (V) of cell.

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13.The sensitivity of a potentiometer refers to the capability of measuring very small potential difference and exhibit change in balancing length even on very small change in potential difference.

The sensitivity of potentiometer can be increased by increasing the number of wires of potentiometer and hence, decreasing the value of potential gradient.

14.The potentiometer works only when(i) the terminal voltage applied by driving cell is greater than the emf of primary cell. (ii) the positive terminals of driving cell and primary cell are connected at the zero end of potentiometer wire.

15.The potentiometer is a better device to measure potential difference than a voltmeter as null point method is used and hence, it can measure even the emf of cell but voltmeter cannot. It measures potential difference with greater accuracy.