plzz clear my doubts

how is trp calculated?if we change the channel during break,then the trp is counted or not.
one thing more,there was a full 10 minutes break between qh telecast.did it happen everywhere.
many people want to watch ipl,so when there is such a long break,they change the channel only in break,but then again watch the show once it resumes.will it effect trps.
if anyone knows,plz clear my doubts.