Question

What is resistance.

Answer 1

Resistance:-It is denoted by "R".Its unit is ohm.It is defined as

$$R=\frac{V}{I}$$

Where V is potential difference and I is current.It is due to resistance that electric wire is heated.Due to resistance the motion of electric charge is opposed.

It is also given as

$$R=\rho \frac{l}{A}$$

Where $\rho$ is resistivity ,l is length and A is cross sectional area of wire.