Plagiarism is not the only form of 'academic misconduct'. There are other types of bad academic practice that are considered to be cheating.
The University has established very clear regulations against cheating, which cover unfair academic practices in all submitted work, from coursework through to departmental tests and formal written examinations. The regulations specify the actions that will lead to you being reported for cheating in an examination. Ignorance of them is not accepted as an excuse if you are caught. If you have broken the regulations unintentionally, you will still be reported for cheating and may be found guilty and have a penalty imposed, such as a mark deduction, or even worse.
It is therefore very important that you understand the regulations and know how you are expected to behave in an examination/assessment. Each year, students are reported for cheating because they have been careless or thoughtless, but had not intended to cheat. You may do something in an exam/assessment without even thinking that it may be viewed as cheating. The consequences can be very unfortunate.
You can view the University of Essex Examination Regulations section on cheating.
If you have any queries please seek further guidance from your department.