the music used in scenes builds tension up, the music is normally slowly then builds up. this also engages the audience making them think that something is going to happen.
suspense is also build by creating cliff hangers. cliff hangers make the audience go the the edge of their seats, this is a good way of ending a opening scene because it makes the audience feel like the movie will be interesting and full of suspense.
The use of false plateau's builds up the tension and also makes the audience think something is going to happen, when it is clear that nothing will happen some directors add the punch.