MCQ Detailed View

Vacuum tubes, also called thermionic valves, were widely used in early electronic devices such as radios, televisions, and the first generation of computers. They controlled the flow of electric current in circuits by creating a vacuum inside a sealed glass tube where electrons could travel freely. Although they played a crucial role in early electronics, vacuum tubes had several limitations:

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  Large in size, making devices bulky.

  
  


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  Generated excessive heat, reducing efficiency.

  
  


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  Consumed high power.

  
  


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  Had a limited lifespan and were prone to failure.

  
  

The invention of the transistor in 1947 revolutionized electronics by providing a smaller, more reliable, and energy-efficient alternative to vacuum tubes. Transistors are semiconductor devices that can amplify signals or act as electronic switches, performing the same functions as vacuum tubes but with many advantages:

1. 
   

   Miniaturization: Allowed the development of small, portable electronic devices.

   
   


2. 
   

   Low power consumption: Operates efficiently using very little energy.

   
   


3. 
   

   High durability: More reliable and longer-lasting compared to vacuum tubes.

   
   


4. 
   

   Faster operation: Supports higher frequencies and improved performance.

   
   

Due to these benefits, transistors completely replaced vacuum tubes in almost all electronic devices, paving the way for modern computers, smartphones, and integrated circuits (microchips) that power today's technology.

The other options are not correct:

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  Conductors: Materials that allow current to flow but do not replace vacuum tubes.

  
  


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  Diodes: Used for rectification and not as universal replacements for vacuum tubes.

  
  

Thus, the correct answer is Transistors, as they successfully replaced vacuum tubes in virtually all electronic applications.