MCQ Detailed View

A Geiger Counter is an electronic device used to detect and measure ionizing radiation such as alpha particles, beta particles, and gamma rays. It is one of the most common instruments used in nuclear physics, radiology, environmental monitoring, and radiation safety. The device is based on a Geiger-Müller tube, which is a sealed container filled with low-pressure gas. When radiation passes through the tube, it ionizes the gas inside. This ionization creates an electrical pulse that is counted and often produces a clicking sound. The faster the clicks, the higher the radiation level.

The unit of measurement often recorded by a Geiger Counter includes:

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  Counts per minute (CPM) – the number of detected particles per minute.

  
  


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  Sieverts (Sv) or rem – which estimate the biological effect of radiation exposure.

  
  

Geiger Counters are widely used in:

1. 
   

   Nuclear industry – to ensure safe handling of radioactive materials.

   
   


2. 
   

   Hospitals – especially in radiology and cancer treatment facilities.

   
   


3. 
   

   Environmental science – for detecting background radiation or contamination after accidents (e.g., Chernobyl, Fukushima).

   
   


4. 
   

   Research laboratories – in experiments involving radioactive isotopes.

   
   

It is important to note that while a Geiger Counter is excellent at detecting radiation, it does not identify the exact type of radioactive isotope. For detailed analysis, more advanced instruments are required.

In Physics, this device plays a critical role in understanding the behavior of nuclear particles and protecting human health from radiation exposure.

Key Fact:

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  Invented by Hans Geiger in 1928 (with Walther Müller).

  
  


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  Still remains one of the most reliable and portable detectors of radioactivity.

  
  

Thus, the correct answer is Radioactivity