Explain the five situations when a no ball is called by an umpire.

An umpire calls a no ball in the following situations: 1. When the bowler's front foot lands beyond the popping crease (a front-foot no ball), or the back foot touches or crosses the return crease. 2. When the bowler throws or jerks the ball instead of bowling it (an illegal action). 3. When the ball bounces more than twice, or rolls along the ground, before reaching the batter. 4. When the ball passes above the shoulder height of the batter standing upright at the crease (a high full toss or a bouncer in excess of the limit). 5. When the fielding side has more than the permitted number of fielders in a restricted area or behind the square on the leg side, or the wicket-keeper is in front of the stumps before the ball reaches the batter.