Q1: The mouth piece shown in the below figure is generally known as

ANS:D - All the above.

It seems that you mentioned a figure, but I don't have the capability to view or refer to external figures. However, based on the description provided, I can explain the terms associated with mouthpieces in fluid mechanics.

1. Internal Mouthpiece: This term generally refers to a mouthpiece that is located within the confines of a pipe or conduit through which fluid flows.
2. Re-entrant Mouthpiece: A re-entrant mouthpiece typically refers to a mouthpiece that extends into the reservoir or container from which fluid is flowing. It re-enters the fluid stream.
3. Borda's Mouthpiece: This is a specific type of mouthpiece named after the French engineer Jean-Charles de Borda. It's characterized by its rounded shape and is designed to reduce contraction losses in the flow of water through an orifice.