Physics 2000 JAMB Past Questions - Question 48: A gas would serve as an electrical conductor under

Correct Answer

B

Explanation

A gas can serve as an electrical conductor under specific conditions, primarily related to its ionization. When a gas is ionized, it means that some of its atoms or molecules have gained or lost electrons, resulting in the formation of ions. In this ionized state, the gas can conduct electricity. Here are some common situations in which a gas can act as an electrical conductor:A gas can serve as an electrical conductor under certain conditions. When a gas is ionized, meaning its atoms or molecules gain or lose electrons, it can become conductive. This ionization can occur through various processes such as high temperatures, exposure to strong electric fields, or exposure to high-energy radiation.

In a process called gas discharge, when a gas is ionized, it forms a plasma, which is a state of matter consisting of charged particles (ions and electrons). Plasmas can conduct electricity and allow the flow of electric current.

Examples of gases that can serve as electrical conductors when ionized include neon lights, fluorescent lamps, and plasma displays. In these devices, the gas is ionized by applying a high voltage or by passing an electric current through it, allowing the gas to conduct electricity and emit light.

It's important to note that not all gases are good conductors, and the conditions required for ionization and conductivity can vary depending on the specific gas and the surrounding environment.

1. **High Temperatures:** When a gas is heated to extremely high temperatures, it can become ionized and conduct electricity. This is the principle behind gas discharge tubes, such as neon signs, where the gas emits light when an electrical current is passed through it.

2. **Electric Discharge:** In some situations, gases can be ionized by a strong electric field. When the electric field becomes sufficiently strong, it can cause electrons to break free from atoms or molecules in the gas, creating ions and allowing for the conduction of electricity. This is the principle behind devices like spark plugs and gas discharge lamps.

3. **Plasma:** Plasma is often considered the fourth state of matter, and it consists of ionized gas. Lightning is an example of a naturally occurring plasma, where the air becomes ionized, allowing electricity to flow through it. Plasma is also used in technologies like plasma TVs and some types of industrial cutting and welding processes.

4. **Gas Discharge Tubes:** Gas discharge tubes, such as neon lamps or fluorescent lamps, utilize ionized gas to conduct electricity and emit light. When a voltage is applied to these tubes, the gas inside becomes ionized, allowing electrical current to flow and producing visible light.

It's important to note that not all gases will readily conduct electricity. The ability of a gas to conduct electricity depends on factors like the gas's composition, pressure, and temperature. In everyday conditions, most gases are insulators and do not conduct electricity. However, under specific conditions, as mentioned above, gases can become electrical conductors when they are ionized.