What is the principle of a potentiometer ? The resistance of a potentiometer wire is $8 \mathrm{\Omega }$. Find the potential difference across the $4\mathrm{\Omega }$ resistor, when the sliding jockey is just in contact at the mid-point $\mathrm{C}$of the potentiometer wire :

What is the principle of potential divider? $\mathrm{AB}$ is a potentiometer wire of length $100 \mathrm{cm}$ and its resistance is $10 \mathrm{ohms}$. It is connected in series with a resistance $\mathrm{R}=40 \mathrm{ohms}$ and a battery of $\mathrm{e}.\mathrm{m}.\mathrm{f}.$ $2 \mathrm{V}$ of negligible internal resistance as shown in figure:

In null deflection position of the galvanometer $\left(\mathrm{G}\right)$, calculate the $\mathrm{e}.\mathrm{m}.\mathrm{f}.$ of the cell $\mathrm{E}$.

Calculate the equivalent resistance between points in following network resistors:

$\left(\mathrm{i}\right)$ Between $\mathrm{A}$ and $\mathrm{B}$

Calculate the equivalent resistance between points in following network resistors:

$\left(\mathrm{i}\right)$ Between $\mathrm{A}$ and $\mathrm{D}$

Find out the reading of voltmeter with the help of the given electrical circuit.