The Trial

Harper Lee creates a significant amount of tension at the trial, and because Scout does not understand everything that is happening, much of the suspense is exaggerated by other people's reactions to the situation. There are several occasions in which Scout comments on Jem reactions to the trial, for example when Atticus confirms with Mr Tate that a doctor was not called "Jem's hand, which was resting on the balcony rail, tightened around it. He drew in his breath suddenly". this helps to build up the tension without directly saying it, as it shows the reader that something is not right without Scout directly stating it.
However, even before the trial has started, tension begins to build up. The reader knows that the trial is important, when we find out that people from all over Maycomb are coming to see the trial, however it seems unusual that Miss Maudie chooses not to go, she says that "just because it's public, i don't have to go, do i?" This makes it seem as if she already knows the outcome of the trial and that she does not what to see it, which could mean that she thinks it could end badly or it could mean that she knows that Atticus knows what he is doing well enough that he can win the case.
The tension is also built up by the way the court room is split up, "the coloured balcony ran along three walls of the courtroom" as if they are taking sides, white versus black. this makes the courtroom seem like a silent war, both sides believe they are right but neither knows for sure, and they are there to find the answer.

I also found a site with a quiz about to kill a mockingbird below:
http://www.gradesaver.com/to-kill-a-mockingbird//study-guide/quiz1