What is electrical resistance? Give a note on it.

(N/A) Electrical resistance is a measure of the opposition to current flow in an electrical circuit. It is defined as the ratio of potential difference across a conductor to the current flowing through it.
The electrical resistance $R$ of a conductor is directly proportional to its length $l$ and inversely proportional to its area of cross-section $A$. That is,$R \propto \frac{l}{A}$.
$R = \rho \left( \frac{l}{A} \right)$,where $\rho$ is the resistivity constant.
The electrical resistance is represented by the symbol $R$ and is measured in ohm $(\Omega)$.
Its $SI$ base unit is $(kg \cdot m^{2}) / (s^{3} \cdot A^{2})$. It can be measured using a Wheatstone bridge.
$1 \, \Omega = 1 \, (kg \cdot m^{2}) / (s^{3} \cdot A^{2})$.
Conversion: $1 \, \Omega \cdot m = 100 \, \Omega \cdot cm$ or $1 \, \Omega \cdot cm = 0.01 \, \Omega \cdot m$.