Question

how to stop sleeping when studying

Answer 1

get up and do some exercise
or wash ur face with cold water
or listen some rock/hip-hop/active music
or do study by taking book in ur hand and walking simultaneously.

Answer 2

1.  Sit upright. Do not read while lying down on the bed or in a slanting position.
2.  Wash the face with warm or cold water. Wipe the face.
3.  Walk a few paces up and down.
4.  Do some exercise if desired.
5.  Drink a hot coffee, tea, Complan, Horlicks, Boost etc.
6.  Accumulate some interest on the subject and lesson that has to be read.
     With some determination, read the books.
7.  It may be preferable to write down what you are reading. So it is better 
     memorized. 
8.  Choose to draw diagrams or work out some problems/exercises. That 
      could be better than reading plain text.
9.  It is better not to take any harmful medicines or to hurt yourself.
10. Talk to someone for a minute and resume study.