Not out. See Law 32.3e (a fair catch). If the ball hits a fielder's protective helmet this is not a fair catch and the batsman is not out, although the ball remains in play.
MCC Laws of cricket: http://www.lords.org/laws-and-spirit/laws-of-cricket/laws/law-32-caught,58,AR.html
However, if the helmet was on the ground and not his head, then the fielding team is penalised 5 runs and the ball is declared dead - he is not out.
5 runs are scored if the batsman hits the ball and the wicketkeeper misses the ball
No, it will be awarded as leg byes. Runs are only credited to the batsman if it comes off his bat or glove.
Batsman is declared as not out
If the helmet is on the batsmens head nothing will happen
When the batsman attempts a shot, he may step outside of his batting crease. If he misses the ball, and the wicketkeeper removes the bails before the batsman returns to his ground, the batsman is out stumped.Stumpings usually occur off spin bowling, as the wicketkeeper needs to be standing up to the stumps in order to affect a stumping. On rare occasions, however, the 'keeper manages to tump a batsman out off a fast bowler.
You may be thinking of being caught. If a fielder catches the ball after it has been hit by the batsman from a valid ball, within the field of play and before it hits the ground then the batsman is out - caught.
A batsman edging the ball and keeper takes his catch is caught behind
Yes, if the ball hits a glove.
Under Law 41 the ball is declared dead and five points are awarded to the batting team.
Yaa, if someone takes a catch then the batsman is out definitely.
The Batsman will get those 5 runs because the ball hits the bat first then the helmet.