Consider the following pairs: 1. Cepheids — Giant clouds of dust and gas in space 2. Nebulae — Stars which…
Consider the following pairs: 1. Cepheids — Giant clouds of dust and gas in space 2. Nebulae — Stars which brighten and dim periodically 3. Pulsars — Neutron stars that are formed when massive stars run out of fuel and collapse. How many of the above pairs are correctly matched?
Only one
Only two
All three
None
Solution
Per the official UPSC key, the answer is C. Pairs 1 and 2 swap descriptions — only Pair 3 is correct; most coaching keys marked A. UPSC officially marked C.