MCQ Detailed View

A positron is a fundamental particle that is considered the antiparticle of the electron. While an electron carries a negative charge (–1e), a positron carries a positive charge (+1e) of the same magnitude. This means the charge of a positron is equal in strength to the charge of an electron but opposite in sign.

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  Charge of positron = +1 elementary charge = +1.6 × 10⁻¹⁹ coulomb

  
  

The discovery of the positron was made by Carl D. Anderson in 1932 during studies on cosmic rays. This discovery was a landmark in physics, confirming the prediction of antimatter made earlier by Paul Dirac through his quantum theory.

Key properties of a positron:

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  Symbol: β⁺

  
  


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  Mass: Equal to the electron (9.11 × 10⁻³¹ kg)

  
  


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  Charge: +1 elementary charge

  
  


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  Nature: Antiparticle of the electron

  
  

When a positron encounters an electron, they undergo a process known as annihilation. In this process, both particles are destroyed, and their mass is converted into energy in the form of gamma-ray photons. This is an important concept in nuclear physics and is widely used in medical imaging techniques like Positron Emission Tomography (PET scans).

Why not the other options?

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  Option 2 (-ve): This refers to an electron, not a positron.

  
  


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  Option 3 (Neutral): Neutral charge corresponds to neutrons, not positrons.

  
  


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  Option 4 (None): Incorrect because the positron definitely has a defined charge.

  
  

Key facts to remember:

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  Positron is the antimatter equivalent of an electron.

  
  


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  It has a positive charge (+1).

  
  


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  Plays an important role in nuclear reactions and PET scans.

  
  


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  First discovered in 1932, confirming Dirac’s theory of antimatter.

  
  

Thus, the correct answer is that a positron carries a +ve charge.