MCQ Detailed View

The Sun, our closest star, goes through a repeating pattern of changing activity levels known as the solar cycle. This cycle refers to the periodic rise and fall of solar activity, which includes phenomena such as sunspots, solar flares, and coronal mass ejections. The duration of one complete solar cycle is about 11 years.

The solar cycle is observed by counting the number of sunspots on the Sun’s surface. Sunspots are darker, cooler regions caused by intense magnetic activity. At the start of a cycle, the Sun has fewer sunspots, indicating low solar activity. As the cycle progresses, the number of sunspots gradually increases, reaching a peak known as the solar maximum, where solar storms and flares are most frequent. After this peak, activity decreases until it reaches the solar minimum, and the cycle begins again.

The solar cycle is driven by the Sun’s magnetic field, which flips polarity approximately every 11 years. This means the north and south magnetic poles of the Sun swap places, completing a full magnetic cycle in about 22 years, but solar activity levels repeat roughly every 11 years.

The effects of the solar cycle can be felt on Earth. During periods of high solar activity, the Sun emits more radiation and charged particles, which can influence:

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  Auroras: Beautiful light displays in polar regions caused by solar particles interacting with Earth’s atmosphere.

  
  


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  Satellite and communication systems: High solar activity can disrupt radio signals and power grids.

  
  


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  Space weather: Increased radiation levels can affect astronauts and spacecraft electronics.

  
  

The correct answer is Option B: 11 years, as this is the average time it takes for the Sun to complete one full cycle of increasing and decreasing solar activity.