1. I would like to ask that when I use accumulate, is it always the active voice? can I use this verb in a passive voice?
2. Is this sentence "Time of each entry will be accumulated" correct? What I want to express in this sentence is that the total time you spend in the study room will all be added up, no matter how many times you come in and out (people have to scan their card every time they come in and out the study)
1. IMHO, accumulate could be either active or passive.
2. "Time of entry" means what time was it when the entry was made. Your 'time of entry' was perhaps 9:15 or 15:54. Best to avoid such potential confusion and use the word duration. From the information you supply, I suggest something like:
Study Room time is cumulative.
The duration of each visit will count toward the total.
Time spent in the Study Room will be accumulated.
Student or Learner