A potentiometer wire has a length 5m and its resistance of $20\mathrm{\Omega }\mathrm{.}20\backslash Omega.$ it is connected in series with a resistance of $1000\mathrm{\Omega }1000\backslash Omega$ and a cell of emf 2V. The potential gradiant along the wire is :

A potentiometer wire, having a resistance of 5 $\mathrm{\Omega }\backslash Omega$ and length 10 m, is connected in series a cell of emf 5 V and an external resistance of 495 $\mathrm{\Omega }\backslash Omega$. A potential difference of 1.5 mV will balance against a length of

A load resistance R is connected across a cell of emf E and internal resistance r. If the closed-circuit p.d. across the terminals of the cell is V, the internal resistance of the cell is

The open-circuit potential difference across the terminals of a cell balances on 150 cm of a potentiometer wire. When the cell is shunted by a 4.9 $\mathrm{\Omega }\backslash Omega$ resistor, the balancing length reduces to 147 cm. The internal resistance of the cell is

To convert a galvanometer into an ammeter

To convert a galvanometer into a voltmeter

An ideal ammeter has

An ideal voltmeter has

The fraction of the total current passing through the galvanometer is

In parallel combination of n cells, we obtain