One of the following is not a radiation detector

Analysis

The question asks us to identify which of the listed devices is not used for detecting ionizing radiation. To solve this, we must evaluate the function of each device in the context of nuclear physics.

Concept Explanation

Radiation detectors are instruments designed to detect, track, and/or identify high-energy particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a nuclear reactor.

• Scintillation chamber: Uses a scintillator (a material that exhibits luminescence when struck by ionizing radiation) to detect radiation.
• Geiger-Muller (GM) counter: Uses a gas-filled tube to detect ionizing radiation by creating an electrical pulse when radiation ionizes the gas inside.
• Film badge: A personal dosimeter used to monitor cumulative radiation exposure. The radiation darkens the photographic film inside the badge, which is later developed to measure the dose.
• Electrophorus: This is an early electrostatic generator used to produce static electricity through the principle of electrostatic induction. It has no mechanism for detecting or measuring nuclear radiation.

Step-by-Step Solution

1. Evaluate Option B (Scintillation chamber): This is a well-known radiation detector used in laboratories to measure radioactivity.
2. Evaluate Option C (Geiger-Muller counter): This is the most common device used to detect alpha, beta, and gamma radiation.
3. Evaluate Option D (Film badge): This is a standard safety device worn by radiographers and nuclear workers to measure radiation exposure.
4. Evaluate Option A (Electrophorus): An electrophorus consists of a dielectric plate and a metal plate with an insulating handle. It is used to generate high-voltage static charges, not to detect radiation.

Since the electrophorus is an electrostatic device and not a radiation detector, it is the correct answer.

Conclusion

The correct option is A.

Exam Tip

When you see "not" in a question, underline it immediately! It is easy to accidentally pick the first correct detector you see (like the Geiger-Muller counter) if you aren't careful. Always scan all options before finalizing your choice.