MCQ Detailed View

Television transmission and display technology rely on converting electrical signals into forms that can be visually perceived. Photo diodes play a key role in this process because they can convert electrical signals into light signals or vice versa, depending on their configuration.

In television systems, electrical signals representing the image data are processed and need to be transformed into visible light to create a picture on the screen. A photo diode is a semiconductor device that responds to an applied electrical signal and emits light (in certain setups, such as LEDs or display pixels) or detects light and converts it into current. In the context of this MCQ, the device used to convert the modulated television signals into light signals for image display is a photo diode or similar light-emitting semiconductor element.

Let's examine the other options:

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  Optical fiber: This is used to transmit light signals over long distances but does not perform the conversion of electrical TV signals into light.

  
  


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  Transistor: A switching and amplifying device; it controls current but does not convert electrical signals directly into light.

  
  


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  Decoder: A circuit that interprets encoded signals but does not produce light output.

  
  


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  Photo diode: ✅ Correct. It is specifically designed to work with light and electrical signals, making it ideal for converting television signals into light that can be displayed to viewers.

  
  

Modern television screens, such as LED, OLED, and LCD displays, contain arrays of photo diodes or light-emitting diodes that turn electrical input into varying light intensities and colors, forming the images we see. This principle is fundamental to electronic display technology and is a key topic in Physics and Electronics.