Question

C(j). How are substances classified on the basis of resistivity? Give one example each class of substance.

Answer 1

Concept used: Resistivity

Step 1: Definition of resistivity

The resistivity of a substance is defined as the resistance offered by a cube of a substance having a side of 1 m when current flows perpendicular to the opposite faces.

Step 2: Classification of substances based on resistivity

The substances are classified into three classes on the basis of their resistivities:

1. Conductors
2. Resistors
3. Insulators

Step 3: Conductors

The substances that show very low resistivity are known as conductors. The conductors allow the flow of electric current through them.

For example, Copper

Step 4: Resistors

The substances that have moderate resistivity are known as resistors. The resistors offer appreciable resistance to the flow of electric current through them.

For example, Nichrome

Step 5: Insulators

The substances that have very high resistivity are known as conductors. The insulators do not allow the electricity to pass through them.

For example, Rubber