Question

Define resistance of a conductor. What is its SI unit?

Answer 1

Concept used: Resistance and Ohm's law

Step 1: Definition of resistance of a conductor:

The flow of a current in a conductor is due to the movement of electrons. The moving electron collides with each other and also with the positive ions in the conductor, which tends to slow down the speed of the electron, and hence there will be opposition in the flow of current. Thus, the property of a conductor to oppose or resist the flow of current through it is called the resistance of a conductor.

Step 2: Definition by Ohm's law:

The resistance of a conductor is directly proportional to the potential difference applied across the conductor and inversely proportional to the current flowing through the conductor.

Step 3: Expression of resistance by Ohm's law:

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

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

Step 4: SI unit of a resistance:

The SI unit of resistance is the ohm, which is derived from the Greek letter omega $\left(\mathrm{\Omega }\right)$.