PSI Barbering Practice Exam

Which of the following is considered a good conductor?

1. Wood

2. Plastic

3. Watery solutions of acids and salts

4. Air

The correct answer is: Watery solutions of acids and salts

The correct answer highlights that watery solutions of acids and salts are considered good conductors due to the presence of ions in the solution. In these solutions, acids and salts dissociate into positively and negatively charged ions when dissolved in water, allowing electricity to flow easily through the solution. This ionic movement is what facilitates conduction. In contrast, materials such as wood and plastic are typically poor conductors. Wood is an insulator under dry conditions, while plastic is generally used as an insulating material in electrical applications due to its inability to allow free movement of electrons. Air is also a poor conductor of electricity, primarily due to its gaseous state, which lacks the necessary charged particles to conduct electrical current effectively. Therefore, the presence of ions in watery solutions makes them the best option for electrical conductivity among the choices given.