Various masaail of Jamaat Salaah and Imaamat

Q: Should we recite when Imam is not reciting in namaaz bajamaat?

Q: If I am in Salaah behind an Imaam and my wudhu breaks, do I complete the Salaah and repeat after or do I walk away at the point where my Salaah broke?

Q: Once I was Imam of Esha prayer, my wudhu broke after the second rakat. I did not know what to do, so I completed the namaz. Now what do I do? There were 11 people behind me.

Q: How many men make a jamaat?

Q: In a Shafie masjid, when the imam makes salams at the end of the prayer, the congregation waits until he has completed both salams, then they make their own salams. Sometimes the salams of the imam are lengthy, making the congregation wait for a long period (longer than 3 subhanallahs). If a Hanafi follower also delays his salam in this manner (waiting for the imam to complete), will his salat become invalid due to delaying a wajib (i.e. intentionally delaying the first salam)?

Q: Is it preferable for the Imam to lengthen the Ruku' briefly when hearing someone entering the Masjid to join the Salaah?

Q: My question is that we read the Alhamdu shareef in our namaz. When we read namaz in jamaat then do we need to read the Alhamudu shareef or not? 

س: لو شك المأموم في الركعة الثانية أنه قرأ الفاتحة في الركعة الاولي ام لا,ماذا يفعل؟

Q: If one wants to pray a Fardh Salah in Jamaat, can one join a person who is praying a Sunnah Salah? What if one joins a person who is praying a Sunnah salah, but you mistakenly assumed that he is praying a Fardh?

Q: When reading salaah behind an imam, what does one read in the standing position (does the person following read surah fatiha and a surah)?