I just want to know that when praying, can we read 2 or more surahs (chapters of Qur'an) in one rakat?
Well the short answer is yes you can read as much of the Quran as you want or can.
This was described in the well known Hadith of the man who didn't pray well (See for example this Version from Sahih al-Bukhari)
...and then recite of what you know of the Qur'an,...
This means you can recite a few ayat or a long ayah or a complete surah or a part of a surah and you can complete a surah and jump and read another. This can be concluded from the sahih hadith (See here the Version of al-Bukhari) about a Sahabi (May Allah be pleased with him) who used to add in the final rak'a surat al-Ikhlass. And an other Hadith from Sahih al-Bukahri and Jami' at-Tirmdihi and an other from Sahih Muslim -which apparently quotes a voluntary qiyam prayer- which is more explicitly answering your Question.
But if you pray in congregation and you are Imam you should also take into account that there are people who can't afford standing long so the Imam shouldn't prolong the prayer too much according to the sahih ahadith (See this hadith with the version from Sahih al-Bukhari and an other hadith from Sahih Muslim here).
And as a practical example in tarawih prayer in Ramadan or qiyam (night) prayer mostly the Imams try to recite the whole Quran in one month so especially at the last night of Ramadan it would be usual to recite many surahs in one raka'a. Or they might start at the end of one surah and begin an other or just recite a part of a surah!
And Allah knows best!