MCQ Detailed View

Quartz watches are among the most common and accurate timekeeping devices used today. They rely on a physical property of quartz crystals known as the piezoelectric effect. This principle is what allows a quartz watch to measure time precisely.

Quartz is a naturally occurring mineral made of silicon dioxide. When a quartz crystal is subjected to mechanical stress, it generates an electric charge across its surfaces. Similarly, when an electric field is applied to the crystal, it begins to vibrate or oscillate at a very precise frequency. This two-way interaction between mechanical pressure and electricity is called the piezoelectric effect.

In a quartz watch, a small battery sends electricity to a quartz crystal, causing it to vibrate at a stable frequency, typically 32,768 times per second. This consistent vibration is converted by the watch’s electronic circuit into regular electrical pulses, which drive the watch’s motor to move the hands or update the digital display. The stability of these oscillations is what makes quartz watches highly accurate, usually losing or gaining only a few seconds per month.

The other options are not correct:

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  Photoelectric effect: Emission of electrons from a surface when exposed to light, used in solar cells.

  
  


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  Stark effect: Splitting of spectral lines in an electric field, related to atomic physics.

  
  


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  Thermionic effect: Emission of electrons from a heated surface, used in vacuum tubes.

  
  


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  None of these: Incorrect, since the right answer is piezoelectric effect.

  
  

This question belongs to Physics, specifically under electronics and oscillation principles. The piezoelectric effect is widely used not only in watches but also in microphones, ultrasound devices, and sensors, making it a key technology in modern engineering.