hi, this is only because you are stressed out and taking too much of tension for the exam. relax and don't worry. sip water while studying.

Dear friend, Your problem as you have explained reveals that your mind gets tired after a particular time. Follow relaxation exercise before starting your practice papers. If it does not work, get help from a psychotherapist Visit www.mastermindfoundation.com Wishes

Hello. You seem very insightful on your problem. You have discovered the pattern of when your concentration dips, and this awareness is a great starting point. Try some deep breathing and relaxation when you become aware of this dip. And then attempt these questions with renewed energy. You could also explore what is it about the questions that doesn't keep you interested/ engaged. You could try and do the latter part of the paper first, to get an idea if it is the time period or the type of questions which maybe related to this loss of concentration. Sometimes we aren't used to sitting for long hours in an alert manner, this is a skill that can be built with practice. Furthermore, you could also consult a counselling psychologist who will help and support you overcome this problem. Good-luck for you exams- Reflective Arena