UPSC Prelims 2024 Question:

Consider the following statements

Statement-I: Giant stars live much longer than dwarf stars. 

Statement-II: Compared to dwarf stars, giant stars have a greater rate of nuclear reactions. 

Which one of the following is correct in respect of the above statements?

Explanation: 

• Giant stars actually have shorter lifetimes compared to dwarf stars. Their massive cores burn through nuclear fuel more rapidly, leading to a shorter overall lifespan. Giant stars have a greater rate of the nuclear reactions that light up stars. Giant stars also use up the hydrogen fuel in their core faster, despite starting out with much more of it. Thus, they live much shorter lives than dwarf stars. So, Statement- I is incorrect.
  
  
• Giant stars, due to their higher mass, have hotter and denser cores. As a result, they experience more intense nuclear reactions, which contribute to their brightness and energy output. Giant stars thus have a greater rate of the nuclear reactions that light up stars. So, Statement-II is correct.
  
  

Therefore, option (4) is the correct answer.

Subject: Science & Technology | Space and Related Developments