Q1: The instrument used for measuring the velocity of flow, is known as

ANS:C - pitot tube

The instrument used for measuring the velocity of flow in a fluid is known as a pitot tube. A pitot tube is a simple and commonly used device in fluid mechanics to measure the velocity of a fluid stream. It works based on the principle of Bernoulli's equation, which relates the pressure of a fluid to its velocity. The pitot tube consists of a small tube with one end pointed into the fluid flow to measure the stagnation pressure (total pressure) and another end connected to a pressure gauge to measure the static pressure of the fluid. By comparing the stagnation pressure with the static pressure, the velocity of the fluid can be determined using Bernoulli's equation. Therefore, the correct answer is: pitot tube.