Q1: The main function of baffles provided in a shell and tube heat exchanger is to

ANS:B - enhance turbulence.

The main function of baffles provided in a shell and tube heat exchanger is to enhance turbulence. Baffles are installed inside the shell of a shell and tube heat exchanger to disrupt the flow of the fluid. This disruption promotes turbulence, which improves heat transfer by enhancing the mixing of the fluid streams and increasing the convective heat transfer coefficient. While baffles can indirectly contribute to facilitating the cleaning of the outer tube surface and holding the tubes in position, their primary purpose is to enhance turbulence and improve heat transfer efficiency. So, the correct answer is: "enhance turbulence."