2024 · Science & TechnologyPrevious Year Question
Q92.
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?
A. Both Statement-I and Statement-II are correct and Statement- I Statement-II explains
B. Both Statement-I and Statement-II are correct, but Statement-II does not explain Statement-I
C. Statement-I is correct, but Statement-II is incorrect
D. Statement-I is incorrect, but Statement-II is correct
Answer

D

Explanation

Giant Stars: Giant stars have masses from eight times to as much as 100 times that of the mass of our sun. These massive stars have hotter and denser cores than dwarf stars (stars that are smaller than five times the mass of our sun). Therefore, giant stars have a greater rate of the nuclear reactions that light up stars. Massive stars also use up the hydrogen fuel in their core faster, despite starting out with much more of it, meaning they live much shorter lives than dwarf stars. A giant star will also end its life in a spectacular fashion, via a supernova explosion, leaving behind a strange object such as a neutron star or an even more bizarre black hole. Statement I is not correct and statement 2 is correct: Giant stars are short-lived due to the faster rates of nuclear reactions. Hence option (d) is the correct answer.