hi,

see at the time of practical exam, your practical work book which you have maintained through out the year  is important and there is specific marks given based on this work book. unless you can not submit the practical work book, you will not get the marks allotted for it, however you would get score for viva voice, attendance, lab work on exam days as well.

so please be cautious while handling your certificates, course work documents, your simple mistake may lead you to big problems in life.