Q. The famous “Alai Darwaza” was built by which of the following?
Explanation: With the arrival of artisans from West Asia the arch and dome began to show up with precision and perfection. Gradually local artisans also acquired the skill.
The tomb of Balban was adorned with the first true arch and the Alai Darwaza built by Ala ud-din Khalji as a gateway to the Quwwatul-Islam Mosque is adorned with the first true dome.
Source: Tamil Nadu NCERT