Question

What are bad conductors?

Answer 1

There are generally three types of materials that are conductors, semiconductors and insulators. Conductors are the materials which allow current to pass through them easily. Semiconductors are materials whose conductivity is between conductors and insulators. Insulators are the materials which do not allow current to pass through them.

Complete answer:
We know that there are three types of materials:
Conductors- Allows current to pass through them easily and have high conductivity. Example- metals.
Insulators- Materials which do not allow current to pass through them. Example-plastic.
Semiconductors- These materials have conductivity between conductors and insulators. Example- Silicon.
So, if we define a bad conductor, then it will be a material which will not allow any current /electricity to pass through it. They are also known as insulators.
This means that a bad conductor will have very low conductivity and high resistance (force which opposes the flow of current/electrons).
Electrons are the charge carriers which produce electricity and if the flow of electrons is highly opposed, then there will be no conduction and hence, the material will be a bad conductor.
Some examples are: mica, wood, glass, rubber, lead etc.

Note:
Insulators will have a high or large energy band gap (between valence band and conduction band) so that the electrons cannot jump from the valence band to conduction band due to this high energy gap while in conductors both the bands overlap each other and hence electrons can jump from valence band to conduction band easily.