The refractive indices of two media are denoted by n₁ and n₂, and the velocities of light in these two media are respectively v₁ and v₂. If n₂/n₁ is 1.5, which one of the following statements is correct?

Which one of the following greenhouse gases is in largest concentration in the atmosphere?

Match List-I with List-II and select the correct answer using the code given below the Lists : 

List - I (Koppens's climatic type)                                List -II (Letter code)

A. Tropical Wet                                                                  1. Af

B. Mid-latitude desert                                                      2. Cs

C. Mediterranean                                                             3. Df

D. Humid Continental                                                      4. BWk

Match List-I with List-II and select the correct answer using the code given below the lists: 

List - I (Railway zone)                List -II (HQ)

A. West central                            1. Jabalpur

B. South east central                  2. Gorakhpur 

C. East Central                            3. Bilaspur 

D. North Eastern                        4. Hajipur

Which one of the followings the correct descending order of Indian states in terms of sex ratio as per Census 2011?