Should the one who is praying behind the imam recite al-Fatihah or listen to the recitation of the imam?
Question

Allah, may He be glorified and exalted, has instructed us to listen quietly and attentively when the Quran is being recited: “So, when the Quran is recited, listen to it, and be silent that you may receive mercy” [al-A‘raaf 7:204]. And the Prophet (blessings and peace of Allah be upon him) warned us that any prayer in which al-Fatihah is not recited is invalid.
I hope that you can tell me what I should do to avoid falling into that which goes against either of these two injunctions, if the imam does not leave enough time for the people praying behind him to recite al-Fatihah. What is the correct opinion regarding this matter?.
Praise be to Allah.In the answer to question no. 10995 we explained that reciting al-Fatihah is one of the pillars or essential parts of the prayer for the imam, the one who is praying behind an imam and the one who is praying on his own. 
Secondly: 
With regard to the pause that some imams leave after reciting al-Fatihah, it is not long enough for the one who is praying behind the imam to recite al-Fatihah; rather it is only a brief pause that serves to separate between the recitation of al-Fatihah and the recitation of another soorah. 
 Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 
The pause between the recitation of al-Fatihah and another soorah was not narrated from the Prophet (blessings and peace of Allah be upon him), despite the view of some of the fuqaha’, that the imam should pause so as to allow those praying behind him to recite al-Fatihah. Rather it is a brief pause that is intended for one to catch one’s breath on the one hand, and to allow the one who is praying behind the imam, on the other hand, to start to recite (al-Fatihah) and he should complete it, even if the imam is reciting, because it is a brief pause, not a long one. End quote.
Fatawa Arkaan al-Islam, p. 323-324 
If the imam does not pause for a long time after reciting al-Fatihah, then the one who is praying behind him has to recite al-Fatihah, even if that is at the same time as the imam is reciting the other soorah, because this is what was the Prophet (blessing and peace of Allah be upon him) instructed his companions to do in Fajr prayer. 
Abu Dawood (823) narrated that ‘Ubaadah ibn as-Saamit (may Allah be pleased with him) said: We were behind the Messenger of Allah (blessings and peace of Allah be upon him) in Fajr prayer. The Messenger of Allah (blessings and peace of Allah be upon him) recited, and he found it difficult to recite (due to interference). When he finished praying he said: “Perhaps you were reciting behind your imam?” We said: Yes, O Messenger of Allah. He said: “Do not do that, apart from the Opening of the Book (al-Fatihah), because there is no prayer for the one who does not recite it.” 
Classed as hasan by al-Tirmidhi; classed as saheeh by al-Bayhaqi, al-Khattaabi and others. This is a clear statement that it is obligatory for the one who is praying behind an imam to recite al-Fatihah in a prayer in which recitation is done out loud. 
Shaykh Ibn Baaz said: If the imam does not pause, the one who is praying behind him has to recite al-Fatihah even if that is when the imam is reciting (the other soorah), according to the more correct scholarly view.
End quote from Fatawa ash-Shaykh Ibn Baz, 11/221 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 
If it is asked: if the imam does not pause, when should the one who is praying behind him recite al-Fatihah? The answer is: he should recite al-Fatihah when the imam is still reciting, because the Sahaabah used to recite al-Fatihah with the Messenger (blessings and peace of Allah be upon him) and he said: “Do not do that except with the Essence of the Book (al-Fatihah), because there is no prayer for the one who does not recite it."(Fatawa Arkaan al-Islam, p. 322)
With regard to the words of Allah (interpretation of the meaning): “So, when the Quran is recited, listen to it, and be silent that you may receive mercy” [Al-A‘raaf 7:204], this is general in meaning, except when one has to recite al-Fatihah, in the sense that it is obligatory to listen attentively to the imam’s recitation of Qur’aan in prayer, except when the one who is praying behind him is reciting al-Fatihah only. This is based on the words of the Messenger (blessings and peace of Allah be upon him): “Do not do that, apart from the Opening of the Book (al-Fatihah), because there is no prayer for the one who does not recite it.” And that was in Fajr prayer, which is a prayer in which recitation is done out loud, as is well known. 
So the one who is praying behind the imam is enjoined to listen attentively except when he is reciting al-Fatihah. 
And Allah knows best.