Time management is very much important in IIT JAM. The eduncle test series for IIT JAM Mathematical Statistics helped me a lot in this portion. I am very thankful to the test series I bought from eduncle.
Nilanjan Bhowmick AIR 3, CSIR NET (Earth Science)
Anshum Sharma
First go through the cartesian, spherical and cylindrical cordinates and their transformation then you can easily understand it. see the attached image