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)
Mahak
acc to str light always travel with speed of light and is never at rest . so photons have zero rest mass this means as photons do not have rest mass they have energy and thus have mass means rest mass is zero and in moving condition mass is due to energy associated with it