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 ?
Show answer
Answer: D. Statement I is wrong: giant (massive) stars live much shorter lives than dwarf stars, sometimes only a few million years. Statement II is correct: their greater mass and core pressure make nuclear fusion run much faster, so they burn their fuel quickly. So I is wrong and II is correct.
Watch for: Bigger seems like it should last longer, but massive stars burn fuel so fast that they die young.
Why the other options are wrong
- A. Wrong because giant stars live shorter, not longer, than dwarf stars.
- B. Wrong because Statement I is false.
- C. Wrong because Statement I is the false one and Statement II is true.
Source to check: NASA Science, 'Stars' (science.nasa.gov/universe/stars): life cycle of stars and how mass sets lifetime
Answer from the official UPSC key. Written and fact-checked by AI against the official key. Spotted a mistake? Report it.