I tried checking flags everyday and they increase to 10 everytime Why are the flags in Ubuntu are limited to 10 and do they get updated every day?? Or there is any limit to flags like 10 flags/day??
The low limit for people who don't have a billion helpful good flags to their record is probably an anti-abuse thing.
Ultimately, when you get higher up in your rep, you get the ability to cast Close Votes rather than Flags. You should look at the Privileges page for info on that, at 3000 rep, which you gain by asking good questions and posting good answers, close votes replace the "duplicate" flags, and are counted separately from flags. But as you're a low-rep person, you're stuck with flags, and until you have a lot of good helpful flags, your limit won't go up very quickly.
If I remember correctly, the more "helpful flags" you've cast, the more your flags limit goes up, but that requires you to do a lot of flagging over time.