Top 250+ Solved Fluid Mechanics and Machinery MCQ Questions Answer
Q. Hydraulic gradient line takes into consideration
a. potential and kinetic heads only
b. potential and pressure heads only
c. kinetic and pressure heads only
d. potential, kinetic and pressure heads
Q. Which of the following is true?
a. egl always drops in the direction of c
b. egl always rises in the direction of flow
c. egl always remains constant in the direction of flow
d. egl may or may not in the direction of flow
Q. Which of the following is true?
a. hgl always drops in the direction of flow
b. hgl always rises in the direction of flow
c. hgl always remains constant in the direction of flow
d. hgl may or may not in the direction of flow
Q. Which of the following is true?
a. hgl will never be above egl
b. hgl will never be under egl
c. hgl will never coincide with egl
d. hgl will may or may not be above egl
Q. The vertical intercept between EGL and HGL is equal to
a. pressure head
b. potential head
c. kinetic head
d. piezometric head
Q. The slope of HGL will be
a. greater than that of egl for a pipe of uniform cross-section
b. smaller than that of egl for a pipe of uniform cross-section
c. equal than that of egl for a pipe of uniform cross-section
d. independent of that of egl for a pipe of uniform cross-section
Q. For a nozzle, the vertical intercept between EGL and HGL
a. increases
b. decreases
c. remains constant
d. may increase or decrease
Q. For a diffuser, the vertical intercept between EGL and HGL
a. increases
b. decreases
c. remains constant
d. may increase or decrease
Q. Which of the following is true?
a. the slope of egl will always be greater than that of the axis of the pipe
b. the slope of egl will always be smaller than that of the axis of the pipe
c. the slope of egl will always be equal to that of the axis of the pipe
d. the slope of egl will always be independent of that of the axis of the pipe
Q. For a fully-developed pipe flow, how does the pressure vary with the length of the pipe?
a. linearly
b. parabolic
c. exponential
d. constant
Q. When a problem states “The velocity of the water flow in a pipe is 20 m/s”, which of the following velocities is it talking about?
a. rms velocity
b. average velocity
c. absolute velocity
d. relative velocity
Q. Which of the factors primarily decide whether the flow in a circular pipe is laminar or turbulent?
a. the prandtl number
b. the pressure gradient along the length of the pipe
c. the dynamic viscosity coefficient
d. the reynolds number
Q. How is Reynolds number defined as?
a. ratio of pressures in the inlet to the outlet of a pipe
b. the product of velocity of the flow and the diameter of the pipe, divided by the kinematic viscosity of fluid
c. the product of density of the fluid, velocity of the flow and the diameter of the pipe, divided by the dynamic viscosity of fluid
d. ratio of inertia force to viscous force
Q. The Reynolds number is found out for a flow in a circular pipe. This circular pipe is moulded into a square pipe, keeping length of the pipe same. Ignore the thickness of the pipe. The Reynolds number changes by
a. 57% decrease
b. 57% increase
c. 43% decrease
d. 43% increase