Final answer:
A manometer connected to a Pitot tube, used for measuring fluid speed by noting the change in fluid height within the tube, is indeed true. This application of the manometer allows for measuring the pressure difference, enabling the calculation of fluid velocity. Option number a is correct.
Step-by-step explanation:
The statement that a manometer is connected to a pitot-static tube for measuring fluid pressure is true. A manometer, typically a U-shaped glass tube partially filled with a fluid like mercury, is used to measure the pressure difference in fluids. When connected to a Pitot tube or a Prandtl tube, it can measure fluid speed based on Bernoulli's principle.
The manometer connects to two points in the flow: one where the fluid has zero speed creating a dead spot, and the other at a point in the flow where the fluid moves across an opening, causing the pressure to drop. The pressure difference is indicated by the change in the height of the fluid column within the manometer, which relates to the velocity of the fluid.