Here is the official answer key.

http://www.upsc.gov.in/exams/answerkeys/2015/CSP_2015/CSP_15_GS_I_AKy.pdf

http://www.upsc.gov.in/exams/answerkeys/2015/CSP_2015/CSP_15_GS_II_AKey.pdf

No need for further mahabharat on controversial questions. Just accept the answer and move on.

What explains the eastward flow of the equatorial counter-current?*
a) The Earth’s rotation on its axis
*b) Convergence of the two equatorial currents*
c) Difference in salinity of water
d) Occurrence of the belt of calm near equator

Official Answer : B

In the South Atlantic and South Eastern Pacific regions in tropical latitudes, cyclone does not originate. What is the reason?
a) Sea Surface temperature are low
*b) Inter Tropical Convergence Zone seldom occurs*
c) Coriolis force is too weak
d) Absence of land in those regions

Official Ans: B

A decrease in tax to GDP ratio of a country indicates which of the following?
1. Slowing economic growth rates
2. Less equitable distribution of national income

Select the correct answer using the code given below.
a) 1 only
b) 2 only
c) Both 1 and 2
d) Neither 1 nor 2
Official Ans: A

Custodian of constitution answer is Supreme Court.

You can put answers of other controversial questions in the comments below.

Cut off for general category is 107.34

Find the category wise cut off pdf attached below

http://upsc.gov.in/exams/cut-off%20marks/2015/CS_2015/CutOff_CSM_2015.pdf