Answers:
Like memos, circulars and notices are also written forms of communication within the organisation. The basic difference between a circular and notice is that circulars are announcements that are distributed to small or selective groups of people within the organisation, whereas notices are meant for a larger group of people. Another way to differentiate a circular and notice is that circular are circulated to respective individuals, whereas notices are put up on notice boards.
For example, if a manager wants to call a meeting of heads of departments, he will pass around a circular only to the heads, requesting them to attend that meeting.